A ratio is a comparison of two or more quantities indicating how many times one value contains another (e.g., 3:1 means there are three of item A for every one of item B).

How do you simplify a ratio?

Divide all terms of the ratio by their Greatest Common Divisor (GCD). For example, 15:20 simplifies to 3:4 after dividing both terms by 5.

What is scale factor?

The multiplier used to scale ratios up or down. If a ratio is scaled by a factor of 3, a ratio of 1:2 becomes 3:6.

Math Tool

Ratio Calculator

Solve, simplify, or compare ratios. Easily find equivalent ratios, scale proportions up or down, and divide quantities into specific ratio groups.

Interactive Ratio Calculator Workspace

Live Solver

C (Optional)

Simplified Form3 : 2Divided all terms by the Greatest Common Divisor (8)

Mathematical Formula & Variables

Equation ModelA : B = C : D => A/B = C/D

A proportion states that two ratios are equal. If three variables are known, the fourth can be calculated using cross-multiplication: A × D = B × C.

Variable Definitions

Symbol	Description
A, B	Terms of the first ratio
C, D	Terms of the second ratio

How to Use the Ratio Calculator

Select your calculation mode: Simplify a Ratio, Solve Proportions (A:B = C:D), or Partition a Value.
For Simplification, enter terms A and B to find their smallest integer form.
For Proportion Solving, enter any three parameters of A, B, C, and D, and leave the target field blank or check its result.
For Partitioning, enter the total value and the ratio terms (e.g., 3:2:1) to see how the total is split.