Proportion Calculator
Use this proportion calculator to solve a missing value in a proportion. Enter the three known values in the proportion and review the unknown value and the matching ratio.
Solved proportion
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Missing value —
Check (both ratios) —
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How it works
If a/b = c/d, then the missing term = (product of the diagonal) ÷ the known termHow to use the Proportion Calculator
Start by entering the three known values in the proportion. Keep the units consistent and check that each value belongs to the same question.
The result gives the unknown value and the matching ratio. Check that the values describe comparable units. Use it as a guide and check any instructions, rules or professional advice that apply.
Frequently Asked Questions
What does this proportion calculator calculate?
It gives the unknown value and the matching ratio. Check that the values describe comparable units.
What information should I enter?
Enter the three known values in the proportion. Use the same units throughout so the result is easier to understand.
Where are proportions useful?
They help compare quantities that change at the same rate.