Reverse percentage calculator
Find the original value before a percentage increase or decrease from the final value.
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: Enter a non-negative percentage. A decrease must be below 100% to recover a unique original value.
Further reading
After a 20% increase the value is 120. The original is 120 / 1.2 = 100. After a 20% decrease, divide 80 by 0.8 to get 100. Subtracting 20% of the final value does not recover the original.
Frequently asked questions
How is the result calculated?
After a 20% increase the value is 120. The original is 120 / 1.2 = 100. After a 20% decrease, divide 80 by 0.8 to get 100. Subtracting 20% of the final value does not recover the original.
What are the limitations?
Enter a non-negative percentage. A decrease must be below 100% to recover a unique original value.
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