Ratio Simplifier Calculator
Reduce a ratio like 18:24 to its simplest whole-number form, and see the equivalent single-number ratio and decimal.
How it works
Divide both terms by gcd(A, B) · A : B = (A ÷ g) : (B ÷ g), where g = gcd(A, B)
A ratio is in simplest form when the two terms share no common factor other than 1. Dividing both terms by their greatest common factor keeps the ratio equivalent while making the numbers as small as possible. Decimal terms are first scaled up to whole numbers so that a ratio like 1.5 : 2 reduces cleanly to 3 : 4.
Worked example
For 18 : 24, the greatest common factor of 18 and 24 is 6. Dividing both terms by 6 gives 3 : 4 — the same ratio in its simplest whole-number form.
Frequently asked questions
How do I simplify a ratio?
Find the greatest common factor (GCF) of both terms and divide each term by it. For 18 : 24 the GCF is 6, so the simplified ratio is 3 : 4.
Can a ratio have decimals?
Yes, but it is usually clearer as whole numbers. This tool multiplies both terms by a power of ten to clear the decimals, then reduces, so 1.5 : 2 becomes 3 : 4.
What if one term is zero?
A ratio like 0 : 5 is already simplest and means one quantity is absent. Only when both terms are zero is the ratio undefined.
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This calculator is for educational purposes. Double-check important results before acting on them.