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Ratio Calculator

Simplify a ratio to its lowest terms, or solve a proportion to find the missing number.

Simplify a ratio

Simplified ratio
2 : 3
A as a fraction of B
2/3
A รท B
0.666667

Solve a proportion A : B = C : ?

2 : 5 = 8 : ?
20

What is Ratio Calculator?

A ratio compares two quantities, such as 12 to 18. Simplifying it to 2 to 3 makes it easier to understand and compare.

What this tool does

The first part divides both numbers by their greatest common divisor, even if they have decimals. The second part solves A : B = C : ? by cross multiplying.

How to use it

  1. Enter the two numbers of your ratio.
  2. Read the simplified ratio.
  3. Use the second part to find a missing value in a proportion.

Did you know?

  • The ratio 3 : 2 is also written as the fraction 3/2 or the number 1.5.
  • Recipes and map scales are everyday uses of proportions.

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