The method of limits which includes derivatives and integrals is also known as analysis. Judging from Webster 1913's definition of calculus which is much broader, it seems that analysis is a more accurate term for this method.

In modern literature, 'calculus' is often used as a synonym for analysis, but apparently only for the more mainstream branches of real and vector variables. For instance complex analysis and tensor analysis retain the original term.

Webster 1913's broader definition is substantiated by the etymology of the word calculus. Originally its only meaning was stone or pebble, which when used in kinds of abacus gained a connection with mathematics.