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LunaCalc

Math

Ratio Calculator

Simplify ratios, solve proportion terms and compare values.

Calculator
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= :
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= :
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times larger is:
times smaller is:

About this calculator

This ratio calculator simplifies a pair of numbers to their lowest whole-number ratio and can scale ratios up or down.

Formula notes

Divide both terms by their greatest common divisor. A ratio a:b is equivalent to ka:kb for any factor k.

Worked examples

  1. Example: 12:18 divides by GCF 6 to become 2:3.
  2. The ratio 84:126 reduces by their GCF of 42 to 2:3; scaling the first term to 10 makes the equivalent ratio 10:15.

How to use it

  1. Enter the two terms of the ratio.
  2. Read the simplified lowest-terms ratio.
  3. Scale it by a multiplier if you need a larger batch.

Frequently asked questions

Is 2:3 the same as 4:6?

Yes. They are equivalent ratios; 2:3 is just the simplest form.

Can a ratio include decimals?

Multiply both terms to clear the decimal first, then simplify as usual.

Limits and interpretation

  • Ratio terms should describe comparable quantities, with units converted before simplification when necessary.
  • A simplified ratio does not preserve the original total or sample size, so context must remain attached.

References