Ratio Calculator

Math & Everyday

Simplify a ratio, divide an amount by it, or solve a proportion.

Runs entirely in your browser — nothing is uploaded

Features

  • Any number of terms, reduced to lowest form.
  • Divides an amount in the ratio, exactly.
  • Solves a : b = c : d for the missing term.
  • Results update as you type, with no button to press.

How to use the Ratio Calculator

  1. 1Enter the parts of the ratio.
  2. 2Add an amount to divide between them.
  3. 3Or switch to proportion mode and leave one box blank.

Frequently asked questions

How do I simplify a ratio?

Divide every term by their greatest common divisor. 20:30:50 all divide by 10, giving 2:3:5. Decimal terms are scaled to whole numbers first, since decimals have no common divisor.

How do I divide an amount in a given ratio?

Add the parts to get the total, then give each share its part divided by that total. Splitting ₹5,000 in 2:3 means five parts of ₹1,000 — so ₹2,000 and ₹3,000.

How do I solve a proportion?

Cross-multiply: in a : b = c : d, a × d equals b × c. Rearranging gives whichever term is missing. Leave exactly one box blank and the tool solves for it.

What is the difference between a ratio and a fraction?

A ratio compares parts to each other; a fraction compares a part to the whole. In 2:3, the fractions are 2/5 and 3/5. The share column shows this conversion.