Calculators

Ratio Calculator

Simplify ratios, compare equivalent ratios, and solve proportions such as a:b = c:x.

Ratio Calculator

Answer
3:4; if 18:24 = 12:x, x = 16
  1. Original ratio: 18:24
  2. Simplified ratio: 3:4

How to use the ratio calculator

The ratio calculator reduces two-part ratios to lowest terms and solves missing proportion values using cross multiplication.

  1. Enter the two numbers in the ratio.
  2. Optionally enter a matching known value to solve a proportion.
  3. Read the simplified ratio and the cross-multiplication step.

Formula or method

a:b = c:x -> a * x = b * c -> x = (b * c) / a.

Worked examples

Simplify a ratio

Problem: 18:24

Solution: GCF is 6, so 18:24 reduces to 3:4.

Solve a proportion

Problem: 3:4 = 12:x

Solution: x = 4 * 12 / 3 = 16.