Proportion Calculator
Solve proportions and find the missing value quickly and accurately.
Enter any three values. Leave exactly one field empty to calculate the missing value.
Proportion Result
What Is a Proportion?
A proportion is an equation showing that two ratios are equal. It can be written as:
When three values are known, the Proportion Calculator can find the fourth missing value.
How to Solve a Proportion
If you have:
Cross multiplication gives:
2D = 24
D = 12
Therefore, the missing value is 12.
Where Are Proportions Used?
Proportions are commonly used in mathematics, cooking, measurements, maps, construction, science, finance, and everyday calculations.
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Frequently Asked Questions
What is a proportion calculator?
A proportion calculator finds an unknown value when two ratios are equal and three of the four values are known.
How many values do I need?
Enter three known values and leave exactly one value empty. The calculator will find the missing value.
Can I use decimal values?
Yes. Decimal numbers such as 2.5, 4.75, and 10.25 are supported.
What formula is used?
The calculator uses cross multiplication to solve A ÷ B = C ÷ D.