Ratio Calculator
Free ratio calculator: enter any two numbers to simplify the ratio to lowest terms, plus the decimal value. Ideal for recipes, maps and homework.
About this tool
A ratio compares two quantities - 12:18 reads \u2018twelve to eighteen\u2019. Simplifying divides both sides by their greatest common divisor, so 12:18 becomes the cleaner 2:3.
Enter any two numbers and this ratio calculator reduces them to lowest terms and shows the decimal value too.
How to use
Type the two numbers and press Simplify Ratio. The tool finds the greatest common divisor, divides both numbers by it, and displays the simplified ratio alongside A divided by B as a decimal.
Decimals are rounded for display; very large numbers are rounded to whole numbers before simplifying.
The math behind it
Simplified ratio = (A / GCD) : (B / GCD), where GCD is the greatest common divisor found with Euclid\u2019s algorithm.
For example, 12 and 18 share GCD 6, giving 2:3 - the same relationship in its simplest form.
Frequently asked questions
What does simplifying a ratio mean?
Where are ratios used in real life?
What is the difference between a ratio and a fraction?
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