Proportion calculator
Find a missing value in a direct or inverse proportion. Follow the calculation with your numbers.
How to 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
Example: 2 kg cost 5 units, so 8 kg cost 20 at a fixed unit price. Direct proportion uses x = b × c / a. Inverse proportion uses x = a × b / c: two people working 8 hours correspond to four people working 4 hours at constant productivity.
Frequently asked questions
How is the result calculated?
Example: 2 kg cost 5 units, so 8 kg cost 20 at a fixed unit price. Direct proportion uses x = b × c / a. Inverse proportion uses x = a × b / c: two people working 8 hours correspond to four people working 4 hours at constant productivity.
What are the limitations?
First check that the relationship is proportional. Fixed charges and changing productivity are not included.
See also
Arithmetic Mean
Enter numbers separated by commas and calculate the arithmetic mean online. The calculator will give you the s
Combinations, variations and permutations
Calculate the number of combinations, variations and permutations of n elements taken k at a time. Combinatori
Decimal to fraction calculator
Convert a terminating decimal into an exact reduced fraction.