Modulo Calculator

About this calculator

This tool computes the quotient and remainder when one number is divided by another — the modulo operation (a mod b) returns just the remainder, the amount left over after dividing a by b as many whole times as possible. For example, 17 mod 5 is 2, because 5 fits into 17 three whole times with 2 left over.

It is used by programmers implementing logic like wrapping a value around a fixed range (clock arithmetic, array indexing, cycling through a list), checking whether one number evenly divides another (a mod b = 0), or distributing items evenly into groups with a leftover. Students also use it to check long-division-style remainder problems in arithmetic and number theory coursework.