Ratio Calculator

Simplify a ratio of whole numbers and view the equivalent reduced fraction and decimal value.

Simplify a ratio

Enter two whole numbers. The first may be zero and the second must be greater than zero.

What is a ratio?

A ratio compares two quantities in a stated order, commonly written A:B. This calculator uses whole numbers so the simplified relationship stays exact.

How to simplify a ratio

Divide both terms by their greatest common divisor. This preserves the same relationship while reducing the terms as far as possible.

Greatest common divisor

The greatest common divisor, or GCD, is the largest positive integer that divides both whole numbers without a remainder.

Ratio vs fraction

A:B and A/B can represent the same numerical relationship, but ratio notation emphasizes comparison while fraction notation emphasizes division or part-to-whole context.

Ratio vs percentage

A percentage expresses a quantity per 100. A ratio does not require a denominator of 100 and can compare any two whole-number quantities.

Worked examples

12:18 has GCD 6, so it simplifies to 2:3. The equivalent fraction is 2/3 and its decimal value is approximately 0.666666666667.

Zero in ratios

A zero first term is allowed, so 0:5 simplifies to 0:1. The second term must be greater than zero because it is also used as the denominator for the fraction and decimal output.

Common mistakes

Reversing the order of the terms.
Dividing only one term by a common factor.
Entering decimals in this whole-number version.

Frequently asked questions

Can I enter decimals?

No. Version 1 intentionally simplifies ratios of whole numbers.

Can A be zero?

Yes. B must still be greater than zero.