Ratio & Proportion Calculator

Simplify mathematical ratios and solve proportions (A : B = C : D) for unknown values.

About this tool

Scale recipes, resize screen aspect ratios, or solve geometry proportions with instant simplification.

How to use this tool

  1. Enter terms A and B to simplify
  2. Optionally enter C to find D

How it works

Computes greatest common divisor (GCD) to reduce terms to lowest whole numbers.

When to use this tool

  • Screen resolution aspect ratios (1920:1080 -> 16:9)
  • Recipe batch scaling

Frequently asked questions

Can it find missing terms?

Yes, if you enter A, B, and C, it will calculate D.

Limitations

Two-term and four-term proportions.

Privacy

Processed locally in memory.