Math Calculators

Proportion Calculator

Check whether two ratios a/b and c/d are equal, forming a true proportion, using cross multiplication.

a × d —

b × c —

Result —

About the Proportion Calculator

A proportion states that two ratios are equal. The fastest way to check whether a/b = c/d holds is to cross multiply: if a × d equals b × c, the ratios are proportional.

Formula: a/b = c/d is true exactly when a × d = b × c

This test is used to verify scale drawings, recipe conversions, similar triangles and unit conversions.