Proportion Calculator

Check whether two ratios are proportional by comparing their cross-products.

How this calculator works

Enter the values for a, b, c, d. The result applies the displayed method and rounds only for presentation.

Formula / method

a ÷ b = c ÷ d when a × d = b × c.

Worked example

Worked example: a = 2; b = 3; c = 8; d = 12.

Assumptions and limitations

The inputs use the units shown and the displayed proportion calculator method applies to the situation being estimated.

This proportion calculator uses the stated formula and supplied units; unusual inputs, local rules or professional context can change the interpretation.