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Ratio Calculator

Simplify ratios, scale them, and solve for a missing value in a proportion.

To work with ratios, choose whether to simplify, scale or solve a proportion. Simplification handles decimals by scaling to whole numbers first, and the result is also shown as a fraction, decimal, percentage and as parts of the whole.

Runs in your browser
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

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 a 2:3 ratio there are five parts in total, so the first quantity is two-fifths of the whole — not two-thirds.

How do I scale a recipe with ratios?

Divide the target quantity by the total number of parts to get the value of one part, then multiply each side of the ratio. For a 2:3 ratio making 500g, one part is 100g, giving 200g and 300g.

How to use the ratio calculator

  1. 1Choose the calculate.
  2. 2Set the a.
  3. 3Set the b.
  4. 4Set the c (or factor).
  5. 5The result appears immediately — copy or download it.

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Put the working ratio calculator on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

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