Ratio Calculator

Simplify a ratio to lowest terms or solve a proportion for a missing term. Handles A:B and A:B = C:x.

Independently verified for accuracy

Calculator by Toolsloft ↗
Simplified ratio
3:4
As a decimal
0.75

Work with ratios two ways. Simplify a ratio like 18:24 down to its lowest terms, or solve a proportion when one of the four terms is missing, such as 2:3 = 10:x. Useful for scaling recipes, mixing ratios, maps, and model builds.

How this is calculated

Simplifying divides both sides of a whole-number ratio by their greatest common divisor, found with the Euclidean algorithm. Solving a proportion uses cross multiplication: for A:B = C:x, the missing term x equals B times C divided by A.

How to use

  1. Choose simplify or solve a proportion.
  2. Enter the known terms.
  3. Read the simplified ratio or the missing value.

Examples

  • Simplify: 18:24 simplifies to 3:4
  • Solve: 2:3 = 10:x gives x = 15

FAQ

How do I simplify a ratio?
Divide both numbers by their greatest common divisor. For 18:24 that divisor is 6, so the ratio reduces to 3:4.
How does solving a proportion work?
For A:B = C:x the tool cross multiplies, so x equals B times C divided by A. With 2:3 = 10:x you get 3 times 10 divided by 2, which is 15.
Why does simplify need whole numbers?
The greatest common divisor is defined for integers. If your terms have decimals, scale them up to whole numbers first, or use the solve mode.

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