Everyday Calculators

Ratio and proportion calculator

Simplify an integer ratio or solve the fourth value of a proportion.

JavaScript is required to run the interactive tool. Open the tool separately if it does not load in the frame.

How to use it

Choose Simplify to enter two integers, or Solve to enter A, B and C for A:B = C:D.

Example

6:9 simplifies to 2:3. If 2:3 = 4:D, then D = 6.

Frequently asked question

How is the missing term computed?

For A:B = C:D, the fourth term is B × C ÷ A.

Limits and privacy

Simplification requires safe integers and rejects 0:0. Solving requires nonzero A and B; magnitudes are limited to 1e15.

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