Modulus is the diminutive from the Latin word modus meaning measure or manner. It, or its plural moduli, may refer to the following:

• Moduli (physics), scalar fields for which the potential energy function has continuous families of global minima
• The measurement of standard pitch in the teeth of a rotating gear
• Bulk modulus, a measure of compression resistance
• Elastic modulus, a measure of stiffness
• Shear modulus, a measure of elastic stiffness
• Young's modulus, a specific elastic modulus
• Modulo operation (a % b, mod(a, b), etc.), in both math and programming languages; results in remainder of a division
• Casting modulus used in Chvorinov's rule.

• Modulus (modular arithmetic), base of modular arithmetic
• Modulus, the absolute value of a real or complex number ( |a| )
• Moduli space, in mathematics a geometric space whose points represent algebro-geometric objects
• Conformal modulus, a measure of the size of a curve family
• Modulus of continuity, a function gauging the uniform continuity of a function
• Similarly, the modulus of a Dirichlet character
• Modulus (algebraic number theory), a formal product of places of a number field
• The modular function in the theory of Haar measure, often called simply the modulus

• Modulus (gastropod) a genus of small sea snails
• Modulus Guitars, musical instrument manufacturer
• Modulus robot, a household robot

• Module (disambiguation)
• Modulo (disambiguation)