Ratio Calculator

What does this tool do?

The Ratio Calculator reduces a ratio to its simplest form and shows its decimal value and percentage split. It also solves proportions of the form a:b = c:d for a missing value, making it handy for recipes, scale drawings, mixtures and financial shares.

How to use it

1. Enter your values into the fields.
2. The result is calculated instantly.
3. Read or copy the result.

Simplifying and solving proportions

In the first section you enter two numbers; the tool computes the greatest common divisor to reduce the ratio to its simplest form, showing 4:6 as 2:3, for example. Alongside it you see the decimal value (a/b) and each side's percentage of the combined total. In the second section you leave the unknown term as 0 in an a:b = c:d proportion; the tool cross-multiplies to solve the missing term automatically and presents the answer in a copyable format.

Everyday use cases

This tool makes life easier when you scale a recipe from 4 to 6 servings, convert a map or model scale to real distance, or adjust mixing ratios for concrete, paint or cocktails. It also gives quick, error-free results for checking aspect ratios, converting a team's gender split into percentages, or working out a proportional profit share. Every calculation runs entirely in your browser.

Frequently asked questions