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Ratio calculator

Simplify a ratio to its lowest terms, or solve a proportion for a missing value — instantly, in your browser.

Simplify a ratio

:

Simplified · decimal

2 : 3 · 0.667

Solve a proportion (A : B = C : x)

:=:

x

15

Percentage calculatorFraction to decimal

Frequently asked questions

How do I simplify a ratio?

Divide both numbers by their greatest common divisor. For 8:12, the GCD is 4, so it simplifies to 2:3. This tool does the GCD for you.

How do I solve a proportion?

For A:B = C:x, cross-multiply: x = B × C ÷ A. For example, 2:3 = 10:x gives x = 3 × 10 ÷ 2 = 15. Enter three values and leave the missing one blank.

What is a ratio as a decimal?

Divide the first number by the second. 3:4 as a decimal is 3 ÷ 4 = 0.75.

Is my data uploaded?

No. TryCalculatingNow calculates in your browser. Nothing you type leaves your device.