In mathematics, a formula is a fact, rule, or principle that is expressed in terms of mathematical symbols. Examples of formulas include equations,
equalities, identities,
inequalities, and asymptotic expressions.

The term "formula" is also commonly used in the theory of logic to mean sentential formula (also called a propositional
formula), i.e., a formula in propositional
calculus.

The correct Latin plural form of formula is "formulae," although the less pretentious-sounding "formulas" is more commonly used.