Calculus is Latin for pebble, and has a number of meanings in English.

Mathematical meanings

Calculus in its most general sense can mean any method or system of calculation.

• In mathematics, calculus most commonly refers to elementary mathematical analysis, which investigates motion and rates of change. The denotation "the calculus" is sometimes used to distinguish this from other mathematical meanings.
• In symbolic logic: the predicate calculus is the rules of inference governing the logic of predicates; and a proof calculus is a framework for expressing systems of logical inference.
• Lambda calculus, a formulation of the theory of reflexive functions with deep connections to computational theory; due in final form to Alonzo Church of Princeton.
• Pi-calculus, a formulation of the theory of concurrent, communicating processes, invented by Robin Milner.
• Join calculus , a theoretical model for distributed programming.
• Theta calculus, a mathematical calculus for the description of stochastic processes, financial portfolios and possible strategies in game theory.
• Tuple calculus, a calculus for the relational data model, inspiring the SQL language.
• Precalculus

Other meanings

• In dentistry, calculus consists of deposits of calcium phosphate salts on teeth, also known as tartar. See calculus (dental)
• In medicine a calculus is a stone formed in the body such as a gall stone or kidney stone. See calculus (medicine)