Many climbing routes have a grade that reflects the technical difficulty—and in some cases the risks and commitment level—of the route. The first ascensionist can suggest a grade, but it will be amended to reflect the consensus view of subsequent ascents. While many countries with a strong tradition of climbing developed grading systems, a small number of grading systems have become internationally dominant for each type of climbing, which has contributed to the standardization of grades worldwide. Over the years, grades have consistently risen in all forms of climbing, helped by improvements in climbing technique and equipment.

In free climbing (i.e. climbing rock routes with no aid), the most widely used grading systems are the French numerical or sport system (e.g. f7c+), the American YDS system (e.g. 5.13a), and latterly the UIAA scale (e.g. IX+). These systems are focused on technical difficulty, which is the main focus of the lower-risk activity of sport climbing. The American system adds an R/X suffix to traditional climbing routes to reflect the additional risks of climbing protection. Notable traditional climbing systems include the British E-grade system (e.g. E4 6a).

In bouldering (i.e. rock climbing on short routes), the most widely used systems are the American V-scale (or "Hueco") system (e.g. V14), and the French "Font" system (e.g. 8C+). The Font system often attaches an "F" prefix to further distinguish it from French sport climbing grades, which itself uses an "f" prefix (e.g. F8C+ vs. f8c+). It is increasingly common for sport climbing rock routes to describe their hardest technical movements in terms of their boulder grade (e.g. an f7a sport climbing route being described as having a V6 crux).

In aid climbing (i.e. the opposite of free climbing), the most widely used system is the A-grade system (e.g. A3+), which was recalibrated in the 1990s as the "new wave" system from the legacy A-grade system. For "clean aid climbing" (i.e. aid climbing equipment is used but only where the equipment is temporary and not permanently hammered into the rock), the most common system is the C-system (e.g. C3+). Aid climbing grades take time to stabilize as successive repeats of aid climbing routes can materially reduce the grade.

In ice climbing, the most widely used grading system is the WI ("water ice") system (e.g. WI6) and the identical AI ("alpine ice") system (e.g. AI6). The related sport of mixed climbing (i.e. ice and dry-tool climbing) uses the M-grade system (e.g. M8), with other notable mixed grading systems including the Scottish Winter system (e.g. Grade VII). Pure dry-tooling routes (i.e. ice tools with no ice) use the D-grade prefix (e.g. D8 instead of M8).

In mountaineering and alpine climbing, the greater complexity of routes requires several grades to reflect the difficulties of the various rock, ice, and mixed climbing challenges. The International French Adjectival System (IFAS, e.g.TD+)–which is identical to the "UIAA Scale of Overall Difficulty" (e.g. I–VI)–is used to grade the "overall" risk and difficulty of mountain routes (with the gradient of the snow/ice fields) (e.g. the 1938 Heckmair Route on the Eiger is graded: ED2 (IFAS), VI− (UIAA), A0 (A-grade), WI4 (WI-grade), 60° slope). The related "commitment grade" systems include the notable American National Climbing Classification System (e.g. I–VI).

In 1894, the Austrian mountaineer Fritz Benesch [de] introduced the first known climbing grading system, which he introduced to rock climbing. The "Benesch scale" had seven levels of difficulty, with level VII the easiest and level I the hardest; as more difficult climbs were made, the grades of level 0 and level 00 were added.^[1]

In 1923, German mountaineer Willo Welzenbach [de] compressed the scale and reversed the order so level 00 became level IV–V, and it became popular in the Alps. In 1967, the "Welzenbach scale" formally became the "UIAA scale" for rock climbing (or "UIAA Scale of Difficulty") with Roman numerals I–VI, and a "+" and "−" to refine each level. The UIAA also incorporated proposals made in 1943 by Lucien Devies [fr] and the Groupe de Haute Montagne [fr] on a broader "Scale of Global Assessment" for alpine climbing (the French Alpine System), and created the "UIAA Scale of Overall Difficulty" by assigning Roman numerals I–VI to the six adjectival levels (e.g. F, PD, AD, D, TD, and ED) of the French system. The UIAA also incorporated a "Scale of Difficulty in Aided Climbing" for aid routes with the levels: A1, A2, A3, A4, and (later) A5. In 1978, the UIAA added the VII (seventh grade) to its "UIAA scale", implying that the scale was open-ended, a concept formally adopted in 1985.^[2]

By the 1980s, French guides had customized the "UIAA scale" beyond V+ with the letters "a", "b", and c" (e.g. V+, VIa, VIb, etc.). At the end of the 1980s, French climbing guidebook author Francois Labande [fr] published the "French numerical scale", which replaced the UIAA Roman numerals with Arabic numerals, and where French 6a equaled UIAA VI+. The two scales were summarised as "Plaisir Grades" and aligned in a UIAA table where French grades 1–6a aligned with "UIAA scale" grades I–VI+; beyond that level, the two systems diverged and for example, French 7a+ equates to UIAA grade VIII and French 9a equates to UIAA grade XI.^[2]

In America, a version of the Welzenbach Scale was introduced for rock climbing in 1937 by the Sierra Club, which in the 1950s was further adapted into the Yosemite Decimal System that added a decimal place to the class 5 grade (e.g. 5.2, 5.3, 5.4, etc.), and which by the 1960s was again amended to introduce the letters "a", "b", "c", and "d" after 5.9 to further refine the levels (e.g. 5.9, 5.10a, 5.10b, 5.10c, etc.).^[2]

While individual countries developed their own rock climbing grading systems, the American system, French system, and latterly the "UIAA scale" became popular internationally (with the American and French dominating sport climbing). The UIAA "Scale of Overall Assessment" dropped its six Roman numbers in favor of the six adjectival grades of the French Alpine System (to avoid confusion with the "UIAA scale") and dominated alpine climbing grading, while the UIAA "Scale of Difficulty in Aided Climbing" – amended and expanded in Yosemite in the 1990s as "new-wave" grades – dominated aid grading.^[2]

The two main free climbing grading systems (which include the two main free climbing disciplines of sport climbing and traditional climbing) are the "French numerical system" and the "American YDS system".^[2] The "UIAA scale" is still popular in Germany and across parts of Central Europe.^[2] Many countries with a history of free climbing have also developed their own free climbing grading systems including the British E-grade system and the Australia/New Zealand "Ewbank" system.^[2]

The evolution of grade milestones in traditional climbing, and latterly sport climbing (as it took over from traditional climbing as the main focus of the leading free climbers), is an important part of the history of rock climbing. As of September 2023, the hardest free climb in the world is the sport climbing route Silence which is in the Hanshelleren Cave, in Flatanger Municipality, Norway; the severely overhanging Silence is graded 9c (French), 5.15d (American YDS), and XII+ (UIAA), and is the first-ever climb to have those grades in history.

The French numerical system for free climbing was developed from the UIAA scale in the 1980s but uses Arabic numbers instead of the UIAA scale's Roman numerals, and also uses the letters "a", "b" and "c" and the "+" symbol to give additional refinement between the numbers (whereas the UIAA uses only the "−" and "+" symbols).^[2] The French system starts at 1 and closely aligns with the UIAA scale up to UIAA V+, which is French grade 6a, but thereafter begins to diverge.^[2][3] The French grading system is the dominant system in Europe, and it and the American YDS system are the most dominant systems worldwide; beyond the easiest grades, the two systems can be almost exactly aligned in comparison tables.^[2][3]

The French system is an open-ended scale that was at 9c in 2023 with Silence. The system is only focused on the technical demands of the hardest movement on the route.^[2] Unlike the American YDS system, there is no allowance for any risks in the route, and thus the French system is more closely aligned with sport climbing (i.e. where pre-bolted protection removes some risk).^[2] It is less common to find traditional climbing routes graded by the French system, and thus it is also called the French sport grade.^[2] To avoid confusion between French grades and the British E-grades, a lowercase "f" (for French) is used as a prefix (e.g. f6a+); this should not be confused with the use of the capitalized "F" or "fb" prefix in Font boulder grades.^[2]

The American YDS (or 'Yosemite Decimal System') was developed independently by climbers at Tahquitz Peak who adapted the class 5 rating of Sierra Club Class 1–5 system in the 1950s.^[4] As a result, the system has a "5" as its prefix which is then followed by a decimal point and a number that starts at 1 and counts up with increasing difficulty (e.g. 5.4, 5.5, 5.6, etc.).^[3] At 5.10, the system adds the letters "a", "b", "c", and "d" as further refinements between levels, and the scale continues upward (e.g. 5.10a, 5.10b, 5.10c, 5.10d, 5.11a, 5.11b, etc.,).^[3][4] The American YDS system is the dominant system in North America, and it and the French numerical system are the most dominant systems worldwide; beyond the easiest grades, they can be exactly aligned.^[2][3]

The American YDS system is an open-ended scale, with the current hardest climb being 5.15d, established by Silence in 2017. Like the French system, the numerical component of the American YDS system is focused on the hardest move on the route.^[4] In 1980, Jim Erickson introduced an additional rating for traditional climbing routes where the level and quality of the climbing protection is assessed.^[4] A suffix of "PG-13" (using the American cinema classification system) denotes the climbing protection is adequate, and if properly placed a fall will be short (in practice, the "PG-13" is usually omitted as it is considered the default).^[4] A suffix of "R" is added where protection is inadequate and any fall could risk serious injury, and "X" for routes with little or no protection and where any fall could be very long and potentially fatal (i.e. also known as a "chop route").^[2][4][3]

American big wall climbing routes will often include the NCCS grade (Levels I–VII) with the YDS grade (e.g. the Salathé Wall at 5.13b VI).^[2]

The UIAA scale (or UIAA Scale of Difficulty) for free climbing was developed from the original "Welzenbach scale" in 1967 and uses the Roman numerals of that scale with "+" and "−" symbols for refinement between numerals after Grade III (i.e. III, IV−, IV, IV+, V−, V, V+ etc.,).^[2][3] Initially, the UIAA scale was closed-ended and went from Grade I (easiest) up to Grade VI (hardest), where it stopped. In 1978, the "seventh grade" was added—though climbers had been climbing at that level for years—and by 1985 it was formally made into an open-ended scale that went beyond Grade VII.^[2][4]

The UIAA scale is closely aligned with the French system up to Grade V+, which is French grade 5a, but thereafter begins to diverge, although the two can be reasonably aligned in comparison tables.^[2][3] The UIAA scale was at XII+ in 2023 with Silence, which is French 9c. While the French system became the dominant scale in Europe, the UIAA scale is still popular in Germany, Austria, Switzerland, Czech Republic, Slovakia, and Hungary.^[2][3][5] The UIAA scale is also commonly found in the grading systems of alpine climbing routes, and particularly those that use the French Alpine System (e.g. PD, D, TD, ED), where the UIAA scale is often used to grade the free climbing component.^[2][6]

The most complex grading system is the British E-grade system (or British trad grade),^[6] which uses two separate open-ended grades for each route.^[7] This structure is particularly adapted to traditional climbing routes (which are more common in Britain), but it is still considered complex and unlike the American YDS system (which has the R/X labels for traditional climbing routes), never came into wider use for traditional climbing outside of Britain.^[7] Within Britain, the French sport grade is more popular for British bolted sport climbing routes.^[7] As of April 2024, the highest consensus E-grade on a traditional route in Britain was on Lexicon (E11 7a) and on Rhapsody (E11 7a), which are considered equivalent to American 5.14 R or French f8b+/f8c+.^[8] Outside of Britain, the highest consensus E-grade was Bon Voyage in Annot, France at E12, or 5.14d / 9a.^[9]

The first grade is an "adjectival grade" that covers the overall difficulty of the route and takes into account the: "seriousness, sustainedness, technical difficulty, exposure, strenuousness, rock quality, and any other less tangible aspects which lend difficulty to a pitch".^[10] This adjectival grade uses the labels (starting from the easiest): M (moderate), D (difficult), VD (very difficult), HVD (hard very difficult), S (severe), HS (hard severe), VS (very severe), and HVS (hard very severe).^[3][10] After HVS, the label switches to E (extreme), but then rises as E1, E2, E3, E4, ... etc., in an open-ended scale.^[3][10]

The second grade is a "technical grade" that focuses on the hardest technical movement on the route. This technical grade has a very similar format to the French sport grade, being an Arabic number that starts at 4 and uses the additional "a", "b", and "c" symbols for refinement between the numbers (unlike the French grades, it does not also use the "+" refinement, and simply goes: 4a, 4b, 4c, 5a, 5b, 5c, 6a, ... etc.,).^[3][10] British climbers use the prefix "f" to distinguish French sport-grades from British technical grades, which is important as they are not equivalent (e.g. British 5c is f6b+).^[2]

The secret to understanding the British E-grade system is the relationship between the two grades.^[2][3][10] For each adjectival grade there is a typical technical grade for a standard route.^[3][10] For example, E4 is often associated with 6a, so E4 6a means the route has a normal level of risk and other related factors for its technical level of 6a.^[11] However, E5 6a would imply that the risk is higher (i.e. closer to an American YDS "R"), while E6 6a would imply a very significant risk (i.e. like the American YDS R/X), and a rare E7 6a would be effectively no protection (i.e. a full American YDS "X", or essentially a free solo route).^[11] Similarly, E3 6a implies a well-protected route, while E2 or E1 6a would imply easily available bomb-proof protection.^[11]

• German/Swiss Saxon scale (or Dresden scale, or East German scale). Developed at the start of the 20th century for the emerging Saxon Switzerland climbing region, it was gradually adopted by other climbing areas in the region, such as Bohemian Switzerland, Bohemian Paradise, Lusatian Mountains, and the Zittau Mountains. While it uses Roman numerals, it is a separate system from the UIAA scale. As well as Roman numerals, the Saxon grades use the symbols "a", "b" and "c" for further refinement between numerals from grade VII onwards. Unlike the American YDS and French sport systems, the Saxon grading system is not purely focused on technical difficulties but is also based on "route length, the total psychological commitment, the placements distance, the risk, [and] the random stops";^[2] it is thus not directly comparable to other systems.^[2]

• Australia/New Zealand/South African Ewbank system. In 1967, Australian climber John Ewbank created his scale as an alternative to the British E-grade, and it became the dominant system for Australia and New Zealand, and latterly for South Africa (with small local variations). The system is open-ended and uses only Arabic numerals (i.e. no "a", "b", "c" or "+" and "−" refinements), starts a 1 (easiest), and continues upward. Unlike many other systems (e.g. American YDS and French sport), the Ewbank system is not solely based on the hardest technical movement on the route but also takes into account the exposure, length, quality of rock, availability of protection, and other factors. Thus, a dangerous route with easier technical climbing might get the same grade as a safe route but with harder technical climbing. The system relies on the climbing guidebook, or word of mouth, to clarify the factors that influenced the grade. For the strongest modern sport climbing routes, the Ewbank grade is largely a technical grade.^[2][3]
• Scandinavian. Norway, Finland, and Sweden have scales that are numerically different (e.g. they don't align exactly), but in effect are very similar and can be aligned in comparison tables. Their scales are all open-ended, use Arabic numerals, and use "+" and "−" symbols for additional refinement between the numerals (e.g. −4, 4, 4+, −5, 5, 5+, 6−, 6, ... etc.,). Originally, the Scandinavian countries used the UIAA scale but its closed-end status at VI (up until 1985) led them to create their own systems, however, they align closely to the UIAA scale, particularly to grade IV. While the UIAA scale is still used in Scandinavian countries, the French sport grade is now more common for sport-climbing routes.^[2][3]
• Brazilian technical scale. Climbing in the carioca dates from 1912 and the ascent of the "Dedo de Deus" (God's Finger) in the Serra dos Órgãos. Brazilian climbing has two grades, with the first being a numerical grade from 1 (easiest) to 8 (hardest) and giving the "overall" level of difficulty (akin to the UIAA Scale of Overall Difficulty). The second, the technical grade, which is the most in use, defines the technical difficulty of the hardest movements (or sequences of movements) and is an open-ended scale that starts with Roman numerals (and a "sup." for additional refinement between numerals), up to VIsup., which is roughly VII+ (UIAA) f6b+ (French) or 5.10d (American). After VIsup., the system moves to Arabic numerals, starting at 7, and using the symbols "a", "b", and "c" for additional refinement between numerals (e.g. VI, VIsup, 7a, 7b, 7c, 8a, etc.,.).^[2]
• Polish Cracow scale (or Kurtyka's scale). Up until the 1970s, the UIAA scale was used in the limestone climbing areas near Kraków, where Polish sport climbing was developed, with Grade I (easiest) to Grade VI (hardest). As the climbing level grew, the UIAA scale became inadequate. Polish climber and alpinist Wojciech Kurtyka proposed an extension to the scale. Easier routes were described by the UIAA scale, and harder routes above Grade VI+ used Arabic numerals with a "+" refinement, so that after Grade VI+ came the new grades of: VI.1, VI.1+, VI.2, VI.2+, and so on.^[12]
• Deep-water soloing grades. A number of systems have been used to assign a "risk" grade for deep-water soloing routes (they typically use the French grading system or American YDS system for the technical challenge). Notable examples include the British S-grades (e.g. S0, S1, S2, S3), which covers the objective risk of the route including tides, under-water objects, height of any potential fall etc.^[13]

The two main boulder grading systems are the French Font-grade and the American V-grade systems.^[2][14] Beyond the easiest grades, the two systems can be almost exactly aligned in comparison tables.^[2][14] For people who have little experience with outdoor climbing, it is also noted that boulder grades on indoor climbing walls tend to feel softer than the equivalent outdoor grades up until about V10 / Font 7C+ (since people climbing at that level generally have plenty of outdoor experience).^[15]

As of September 2023, the hardest bouldering route in the world is Burden of Dreams in Lappnor in Finland, which is graded 9A (Font) and V17 (V-grade/Hueco), and was the first-ever boulder to reach those grades.

The Font-grade system is easily confused with the French sport grade and the British E-grade systems as they use similar symbols, however, boulder grades are very different from free climbing grades and they start at much harder technical levels. For example, the entry-level Font-grade 4 / V-grade V0 is equivalent to the free climbing grades of 6a to 6a+ (French), VI to VII− (UIAA), and 5.9 to 5.10c (American YDS), depending on what table is used.^[2][4][5]

This confusion is amplified by the tendency for modern sport-climbers to describe the crux moves on their routes in terms of their bouldering grades – their routes are effectively a series of connected boulder problems. For example, here is Adam Ondra describing his 2017 redpoint of Silence, the first-ever free climb in the world to carry a grade of 9c (French), 5.15d (American), XII+ (UIAA):

The climb is about 45m long, the first 20m are about 8b [French sport] climbing with a couple of really really good knee-bars. Then comes the crux boulder problem, 10 moves of 8C [French boulder]. And when I say 8C boulder problem, I really mean it. ... I reckon just linking 8C [French boulder] into 8B [French boulder] into 7C [French boulder] is a 9b+ [French] sport climb, I'm pretty sure about that.

— Adam Ondra in an interview with PlanetMountain (2017).^[16]

In addition, boulder routes that connected various boulder problems into a single longer bouldering route have been graded as if they were sport climbs. A notable example is the 2004 boulder route The Wheel of Life, which is graded V15 (8C) as a boulder route, but also f9a (5.14d) as a sport climbing route.^[17]

The Font-grade (from the "Fontainebleau climbing area") is one of the oldest boulder grading systems whose origins can be traced back to at least 1960 with Michel Libert's L'Abbatoir at Fontainebleau.^[14] The Font-scale is an open-ended scale that starts at 1 and increases in single-digit steps but uses a "+" for additional refinement between steps; from grade 6 it introduces a capitalized "A", "B" and "C" for further refinement, and was at 9A in 2023 with Burden of Dreams. The Font-scale has no regard to any risk and is purely focused on the technical difficulty of the movements.^[2] The Font-scale is distinguished from the French sport grade by using capitalized letters (i.e. Font 6C+ vs. f6c+), and also the use of "Fb" or capital "F" (for "Font") as a prefix. The distinction is important as the scales are very different (i.e. Fb6C+ is closer to f7c).^[2][14]

The V-grade (short for "Vermin" or "Verm", and also known as the "Hueco" scale) was first published in 1991 by American bouldering pioneer John "Verm" Sherman in his climbing guidebook, Hueco Tanks Climbing and Bouldering Guide.^[14] Legend is that his publisher would not print the book without some kind of rating of his 900 routes.^[14] The V-scale is an open-ended scale that starts at V0 (although a slightly easier "VB" has been used for beginners), and increases in single-digit steps (i.e. V5, V6, V7), and was at V17 in 2023 with Burden of Dreams. The V-scale doesn't consider risk and is purely focused on the technical difficulty of the movements.^[2] The V-scale is the dominant scale in North America, and it and the Font scale are the most dominant systems worldwide; beyond the easiest grades, the two systems can be almost exactly aligned in comparison tables.^[2][14]

• Japanese Dankyū system. Also known as the "kyū dan" system, is widely used in Japan, and is constructed in a way that resembles martial arts grading systems (see Dan and Kyu). Developed in the Japanese bouldering area of Ogawayama, the system begins at 10-kyū (easiest) and gets progressively harder as it counts down to 1-kyū. As with martial arts grading, after 1-kyū the system uses "black-belt grades" of 1-Dan (or shodan, "the first step"); 1-Dan is roughly equal to a V7 grade, while 6-Dan (or rokudan) is at V16.^[14]
• American "B" system. Created by American bouldering pioneer John Gill in 1958,^[14] it contained just three grades: B1 (easiest), B2, and B3 (hardest). B1 was "the highest level of difficulty in traditional roped climbing" (which was about American YDS 5.10 (or French 6a / UIAA VI+) at that time,^[14] B2 was "harder than anything in B1",^[14] and B3 was a "route that had been tried on multiple occasions by more than one party but had only been climbed once" (i.e. if a B3 was repeated it would be immediately reclassified as a B2, or even a B1).^[14][18]
• British Peak B-grade. The peak district in Britain is an important bouldering area and had developed a bouldering scale that was very similar to the V-grade scale except the pre-fix "B" was used and it started at B1 (i.e. B1, B2, B3, B4, ... etc.). Peak B-grades are roughly one level easier than V-grades (e.g. V8 was equivalent to B9). The V-grade / Font-grade systems (sometimes the "technical grade" component of the British E-grade system is used) have replaced Peak B-grades in Britain but they appear in some guidebooks and some boulder grade conversion tables.^[3][10][19]

The main aid climbing systems are the A-grade (usually the "new wave" version) and the C-grade systems.^[2][20][4] While aid climbing is less popular as a standalone pursuit, aid techniques remain important in big wall climbing and alpine climbing, where the level of difficulties can vary significantly on long routes, and thus the use of aid in places is still common (e.g. The Nose on El Capitan is graded '5.9 (American) C2 (aid)' with aid, but an extremely difficult '5.14a (American)' without any aid; guidebooks will mark such routes as '5.9 & C2 (5.14a)', with the no-aid/fully free option in brackets.^[20]

The grade of an aid climbing route can change materially over time due to improvements in aid equipment but also due to the impact of repeated ascents that subsequent aid climbing teams make to a route.^[22][23] It is not uncommon for a new A5 route in Yosemite to become a "beaten-out A3+ route" due to the effect of repeated hammering of cracks (which widens them), and to the build-up of permanent in-situ aid climbing equipment.^[24]

The original "UIAA Scale of Difficulty in Aided Climbing" system went from A0 to A5 and focused on the number and quality of "bodyweight placements" (i.e. can only take static bodyweight and not a falling bodyweight) versus "bombproof placements" on a given pitch.^[2][24] The grades were less concerned with the physical demands of the route (although there was some mention), and risk was only introduced later with A5.^[22][24]

In the 1990s, Yosemite aid climbers created what they called a "new wave" aid grading system that expanded the range of the original UIAA system to A6 (they had already re-defined parts of the UIAA system), and introduced an intermediate "+" grade from A2 onwards for specific tricky or strenuous sections, and gave more detailed definitions at each grading level than the original A-grades.^[24][22]

When the original or the "new wave" aid climbs can be ascended without the use of a hammer (for pitons or copperheads), the "A" suffix is replaced by a "C" to denote "clean climbing".^[25][26] In Yosemite, an "F" suffix is placed after the "C" if fixed gear (e.g. bolts) is required to go clean (or hammerless).^[24]

The most dominant system internationally for ice climbing is the WI-grade, while the most dominant international system for mixed climbing is the M-grade (with the Scottish Winter grade also notable given the unique nature of Scottish mixed routes).^[27] Where a route has no ice, and not even the "thin ice coating" common on Scottish Winter routes, it is increasingly common to use a D-grade to indicate dry-tooling. Some M-graded routes in "dry" areas (i.e. places like the American Rockies, but not Scotland), are more of a combination of a WI-graded ice route with a D-graded dry-tooling route.^[2][25][26]

The most dominant ice climbing system is the WI (for "water ice") grading system.^[28][27] WI-grades broadly equate to the mixed climbing M-grades from WI1 up to WI6/WI7, but after M6/M7, mixed climbs become overhanging, which ice does not.^[28][27] WI-grades try to take some account of the difficulty of placing protection on the route but, as with M-grades, are more focused on the technical and physical challenge of the route, and are thus more akin to the French and American YDS free climbing systems, although as with the American YDS system, an "R/X" suffix is sometimes used alongside the WI-grade to grade additional risks.^[28][27]

The WI-grade is for "hard ice"; steep snow slopes, which are encountered frequently on alpine climbing routes, are not explicitly graded but instead, their steepest angle (approximate figure or a range) is quoted (e.g. 60–70 degree slope).^[25][26] WI-grade is for "seasonal" hard ice; an AI prefix is used instead for "alpine ice", which is year-round and usually firmer, more stable, making AI-grade routes slightly easier than WI routes.^[25][26]

In 2010, ice climbers began to put up new ice routes at Helmcken Falls in Canada that had unique characteristics. Unlike the sheerest WI7 ice routes, these routes were significantly overhanging like extreme M-graded routes. This was due to the intense spray from the waterfall, which covered the overhanging routes in ice so that there was little dry-tooling (i.e. all the movement was on hard ice).^[29] The routes were bolted like M-grade climbs and the result was a series of new WI-graded routes that laid claim as the "world's hardest ice routes"; by 2020, they reached WI13 with Mission to Mars.^[29]

The grading of mixed climbing routes approximates the ice climbing WI grades, up to M6, but they then diverge as mixed routes can become very overhanging and eventually turn into roofs (ice is not normally overhanging, aside from Helmecken Falls routes).^[28][30][27] M-grades do not take into account the "danger" of the route (i.e. how good is the protection in the event of a fall) as they are mostly pre-bolted routes; they, therefore, focus on the technical and physical challenge of the route, and is thus more akin to the French and American free climbing rock grades, although as with the American system, the "R/X" suffix is used for danger.^[28][30]

In his 1996 book, Ice World, mixed climbing pioneer Jeff Lowe ranked his new M-grades to the level of physical exertion needed on a free rock climb; for example, Lowe estimated that M8 was equivalent to 5.12 (American YDS).^[27] Other authors have tried to align M-grades with rock climbing grades,^[4][31] and now equate M8 to 5.10/5.11, however, there is some variation and no consensus that such comparisons are valid.^[27]

When mixed climbing is done as pure dry-tooling, which is ice climbing on bare rock with no ice section, the M-grade is usually replaced by a "D" grade prefix (but all other aspects of the two systems are identical).^[2] The most extreme dry-tooling route in 2023 is Parallel World (D16) in the "Tomorrow's World Cave" in the Dolomites.^[28][32]

Mixed climbing in Scotland is known as "Scottish Winter climbing" and uses a dual-grading system – similar to the British E-grade – with a Roman numeral denoting the "overall" difficulty (e.g. technical challenge, length, and the level of boldness/physicality/stamina required).^[30] A second Arabic number grades the technical difficulty of the hardest move on the route.^[30] A climb graded (VI, 6) means the difficulty of the hardest move is standard for the overall grade, whereas a climb graded (VI, 8) denotes the hardest move is above the overall grade.^[30]

This dual grade is needed as Scottish winter climbs use traditional climbing protection, placing greater strains on the climber.^[30] British climber Ian Parnell wrote in his guide to Scottish winter climbing that Scottish grades are almost two levels above M-grades, and thus a Scottish (VIII, 8) is similar to an M6; but that an onsight of a Scottish VIII, 8 using traditional climbing protection, would be similar in difficulty to a bolted sport climbing M8.^[30]

• Canadian Ice. Canadian ice climbs quote both the Canadian Winter Commitment Grade, with Roman numerals 1–7 for the "overall" challenges and risks, and a "technical scale" that uses Arabic levels 1–7 for the hardest movements. Other grades can be provided to reflect the mixed climbing (M-level), the thickness of the ice (R-level), and the fragility of the structure (X-level). In practice, Canadian Ice "technical grades" are equivalent to the WI-grade, but omit the "WI"; a typical route could be graded as III-4.^[2][27]
• New England Ice (NEI). A system was developed in the 1970s in New England that used NEI levels 1 to 5 (and a later level of 5+) to grade ice routes, which in effect equated to the WI-grades of WI1 to WI5 (and NEI 5+ at WI6). The NEI levels are considered to be slightly "harder" than the equivalent WI-grades. Following the international trend, the WI-system is now commonly used in New England.^[4][27]

The most important grading system in mountaineering is the International French Adjectival System (IFAS) (or French Alpine System, FAS), which is also effectively the "UIAA Scale of Overall Difficulty" (they are the same, only differing in labels), and which is used in all forms of alpine climbing around the world.^[2][34]

Due to the complexity and length of mountaineering and alpine climbing routes, their grading systems are focused on the "overall" – or "global level" – of risk and/or commitment of the route.^[2][34] The specific rock climbing, aid climbing, and/or ice and mixed climbing difficulties of the route will be graded separately (per the earlier grading systems) and listed alongside the mountaineering grade (e.g. see photo opposite).^[2][3][34]

For a time, there were a number of "commitment grade" systems that primarily focused on the amount of time required for the route (e.g. Grade I being several hours to Grade VII being several weeks), such as the American National Climbing Classification System (NCCS), but for various reasons these are now in less use.^[2][3][34]

The IFAS system (or UIAA Scale of Overall Difficulty), also called the French Alpine System (or Alpine System),^[3][26] grades the overall difficulty of a route, taking into account the length, technical difficulties, exposure, and commitment level (i.e. how hard is a retreat).^[4][34] The system was created by French climbers, and when the UIAA formally adopted it in 1967 they assigned Roman numerals to the six levels, which caused confusion with the UIAA scale, and thus the French shorthand for the six levels prevailed:^[2] F–Facile (easy), PD–Peu Difficile (not very difficult), AD–Assez Difficile (fairly difficult), D–Difficile (difficult), TD–Très Difficile (very difficult), and ED-Extrêmement difficile (extremely difficult).^[3][4][26]

Later, a + (pronounced Sup for supérieur) or a − (pronounced Inf for inférieur) was used to indicate if a particular climb is at the lower or upper end of that grade (e.g., a climb slightly harder than "PD+" might be "AD−"), and the specific degree of the snow slopes was added (e.g. 60 degrees).^[2]

As standards rose, the ED-grade was further expanded into ED1 (is the original ED−), ED2 (is roughly the original ED), ED3 (is the original ED+), ED4, ED5 .. etc., to denote harder levels of grade.^[2][34]

Whilst each IFAS grade can imply certain grades of rock, ice, or mixed climbing difficulties, the UIAA warns against assuming the IFAS grade always aligns with specific rock and ice climbing grades, as the objective dangers can vary dramatically on alpine routes with similar rock and ice climbing grades. For example, the famous 1,800-metre 1938 Heckmair Route on the north face of the Eiger has an IFAS ED2-grade even though the rock climbing is only at UIAA VI− and the ice climbing at 60 degrees (or WI-4 grade), which is more typically associated with an IFAS D-grade; this is due to the exceptional length and serious dangers of the route.^[2][3] Some guidebooks have still attempted to list the implied rock and ice climbing grades at each IPAS level.^[3][35][34]

The National Climbing Classification System (NCCS) was devised in the 1960s by the Sierra Club as "commitment grade" for mountaineering routes, and in particular, the time investment in a route for an "average" climbing team".^[25][26] The NCCS uses Roman numerals form Grade I (few hours of climbing) to Grade VII (several weeks of climbing).^[25][26] The NCCS was popular for a period on American big wall climbing routes, however, advancements in techniques and the ability for climbers to complete big wall routes in hours that historically took days (or weeks), made the NCCS less useful; it is still often quoted on American big wall routes (although it is often confused as being the UIAA scale).^[2][4][34] NCCS grades are described as:^[25][26]

• NCCS Grade I and Grade II: "Half a day or less for the technical (5th [i.e. Yosemite Decimal System grade] class) portion of the route".^[25][26] Often listed as "1–3 hours" (for grade I), and "3–5 hours" (for grade II).^[36]
• NCCS Grade III: "Most of a day of roped climbing".^[25][26] Often listed as "5–8 hours".^[36]
• NCCS Grade IV: "A full day of technical climbing".^[25][26] Often listed as "a full day".^[36]
• NCCS Grade V: "Typically requires an overnight on the route, or done fast and free in a day".^[25][26] Grade V is often listed as "one very long day of climbing, or two full days of climbing".^[36]
• NCCS Grade VI: "Two or more days of hard climbing".^[25][26] Often listed as "two days to a week".^[36]
• NCCS Grade VII: "Remote walls climbed in alpine style".^[25][26] Often listed as "more than a week of hard climbing in extreme (i.e. alpine) conditions".^[36][3]

The Russian grading system has a range from grade 1A–6B that aligns in comparison tables with the IFAS/UIAA system (the six levels align with the original six UIAA Scale of Global Difficulty levels),^[2] and factors in difficulty, altitude, length, and commitment (i.e. risk and difficulty of retreat); the grades are described as:^[25][26]

• Russian Grade 1B: Some easy roped climbing.^[25][26]
• Russian Grade 2A: Several pitches of easy roped climbing.^[25][26]
• Russian Grade 2B: Some (UIAA scale) II+ and III climbing on a multi-pitch route.^[25][26]
• Russian Grade 3A: Contains 1 to 1.5 pitches of III climbing on a multi-pitch route.^[25][26]
• Russian Grade 3B: One or two pitches of III+/IV climbing on a full-day route.^[25][26]
• Russian Grade 4A: A full-day route with IV+ climbing.^[25][26]
• Russian Grade 4B: Several pitches of IV+ or some V+ climbing.^[25][26]
• Russian Grade 5A: Contains several pitches of V climbing on a 1- to 3-day route.^[25][26]
• Russian Grade 5B: Two-plus days with some VI+ climbing.^[25][26]
• Russian Grade 6A and 6B: Multi-day routes with considerable VI or harder climbing.^[25][26]

In the "Alaskan Overall Difficulties" system,^[2] mountaineering routes are graded from 1 (easiest) to 6 (hardest), and factor in difficulty, length, and commitment (including storms, cold, and cornicing).^[4] The system was developed by Boyd N. Everett Jr. in 1966, for the particular challenges of Alaskan climbing,^[2] and rarely appears outside of the region.^[25][26] A summary of the levels from Alaska: A Climbing Guide (2001) is:^[25][26][34]

• Alaska Grade 1: Climb requires one day only, no technical (fifth-class) climbing.
• Alaska Grade 2: Either a moderate fifth-class one-day climb, or a normal multiday nontechnical climb.
• Alaska Grade 3: Either a serious fifth-class one-day climb, or a multiday climb with some technical elements.
• Alaska Grade 4: Multiday, moderately technical climb.
• Alaska Grade 5: Multiday, highly technical climb.
• Alaska Grade 6: Multiday, extremely technical climb.

A plus (+) may be added to indicate somewhat higher difficulty. For example, the West Buttress Route on Denali is graded 2+ in the aforementioned guidebook. Importantly, even an Alaska Grade 1 climb may involve climbing on snow and glaciers in remote locations and cold weather.^[2]

• Canadian Winter Commitment Grade. This system has seven levels denoted by Roman numerals I–VII, and is similar to the NCCS grading system, being focused on the time commitment needed to complete the route with some regard to the increasing technical difficulty and the number of pitches and challenges that may be encountered; as with the NCCS system, it is less used today.^[25][26][34]
• New Zealand Mount Cook system. The "Mount Cook" system was proposed by Hugh Logan in his 1982 guidebook The Mount Cook Guidebook with NZ levels 1–7 (and a "+" prefix for refinement between levels) that roughly matched the six IFAS/UIAA levels, and with NZ level 7 at IFAS ED2/3.^[25][26] Logan's system was used for several decades until a new version was proposed by Robert Frost in his 2018 guidebook Aoraki Tai Poutini that had two sets of grades: Level I–VII for seriousness and commitment, and Level 1–8 for the technical challenge (rock, ice and mixed climbing).^[34]

Free climbing systems can be broadly compared per the table below.^[26][25][38] While most systems do not perfectly align, especially at the lower (or easier) grades, above the level of circa 5.12a (American YDS), f7a+ (French), VIII+, the sport climbing becomes the dominant free-climbing format and most grades closely align;^[2][3] the exception being the traditional climbing focused British E-grade system.^[7]

Main sources: RockFax Rock Climbing Grade Table (2021),^[3] theCrag (2023),^[38] and UIAA (2021).^[2]

As of 2023, the American and French bouldering grade systems can be compared in the following way (they exactly align after V9 / 7C).^[2][3][38] Various authors have created tables to compare bouldering grades of Font/V-grade, to the free climbing French sport/American YDS grades, but because of the different types of climbing (and particularly the sequences of movements), they are only ever indicative and can vary by several levels between versions;^[2][4][5] an example is provided in the table below from a report by the Club Alpino Italiano for the International Climbing and Mountaineering Federation from 2016.^[2]

Main sources: RockFax Bouldering Grade Table (2021),^[3] theCrag (2023),^[38] and UIAA (2021).^[2]

As of 2023, the Russian system can be compared to the French Alpine System (and the UIAA Scale of Overall Difficulty), in the following way:^[2][34]

Main source: UIAA (2021)^[2]

• Beta (climbing)
• History of rock climbing
• Trail difficulty rating system

• The Mountaineers (2018). "Appendix A: Rating Systems". Mountaineering: The Freedom of the Hills (9th ed.). Quiller. ISBN 978-1846892622.
• Mandelli, G; Angriman, A (2016). "Scales of Difficulty in Mountaineering". Central School of Mountaineering, Club Alpino Italiano, Italy.
• Nick Draper; David Giles; Volker Schöffl; Franz Konstantin Fuss; Phillip Watts; et al. (October 2015). "Comparative grading scales, statistical analyses, climber descriptors and ability grouping" (PDF). Sports Technology. 8 (3–4): 88–94. doi:10.1080/19346182.2015.1107081. S2CID 111441279.
• "International Grade Comparison Chart". American Alpine Journal. 2013.

• Climbing Grades Explained, HardClimbs (June 2023)
• RockFax Climbing Grade Conversions, RockFax Publishing (2023)
• International Climbing Grade Comparison Chart (Rock and Boulders), MountainProject (2023)
• Grades and Grade Conversions, theCrag (2023)
• UIAA Grades for Rock Climbing, UIAA (2023)
• Grading of Climbs, Ari Paulin Base Camp Database (2023)
• (Comparative Grades Table) Reporting Grades in Climbing Research, International Rock Climbing Research Association (2015)