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Enter two integers
The first may be zero; the second must be greater than zero.
Math
Free tool
Ratio Calculator
Simplify a ratio of whole numbers and view the equivalent reduced fraction and decimal value.
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Simplify a ratio
Enter two whole numbers. The first may be zero and the second must be greater than zero.
Result
How to use this calculator
Three steps to an answer you can interpret.
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Simplify the ratio
The calculator divides both terms by their greatest common divisor.
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Read equivalents
Use the simplified ratio, fraction and decimal to interpret the relationship.
Understand the result
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.
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.
The order matters: 2:3 and 3:2 describe different relationships.
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.
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.
More useful tools
View allFrequently 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.