Proportion calculator
Find a missing value in a direct or inverse proportion. Follow the calculation with your numbers.
How do I use this page?
- Enter values or use the example in the form.
- Choose a mode or units where available.
- Read the result and check the calculation steps below.
What this page does not do: First check that the relationship is proportional. Fixed charges and changing productivity are not included.
Further reading
Theory — how do you solve direct and inverse proportions?
The proportion calculator finds a missing value in a direct or inverse proportion and shows the formula with your own numbers substituted in. In a direct proportion, if 2 kg costs 5 zł, then at a constant unit price 8 kg costs 20 zł, following the formula x = b × c / a. In an inverse proportion the formula is x = a × b / c — for example, two people working for 8 hours complete the same job as four people working for 4 hours.
Frequently asked questions
How is the result calculated?
What are the limitations?
See also
Ancient Egyptian units converter
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Basic calculator
Add, subtract, multiply and divide with parentheses and percentages.