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Ratio Calculator

Solve for a missing term in a proportion, simplify ratios, or scale one ratio up or down.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

If a : b = c : d, then a × d = b × c. Solve for whichever term is missing.

In depth

Solve for a missing term in a proportion, simplify ratios, or scale one ratio up or down.