integral calculus In mathematics, branch of calculus that deals with integration: the finding of a function, one or more derivatives of which are given. There are many applications of integral calculus. It is used to find the areas and volumes of curved shapes. In engineering calculations, differential equations are solved by integral calculus. Its principles are also incorporated in many measuring and control instruments.

in·te·gral cal·cu·lus • n. a branch of mathematics concerned with the determination, properties, and application of integrals. Compare with differential calculus.