Reverse Percentage Calculator
Recover an original value from the final amount and a known percentage increase or decrease.
What would you like to do next?
Work backward from the value after a percentage change
Supply the final amount and the percentage change that produced it. A positive percentage represents an increase, while a negative percentage represents a decrease. The calculator divides the final amount by the corresponding multiplier, then shows the recovered starting value and the absolute change. This avoids the common mistake of subtracting the same percentage from the final number.
Keep the direction and denominator clear
An increase of twenty percent uses a multiplier of 1.20; reversing it requires division by 1.20, not a twenty-percent reduction. A decrease of one hundred percent has a zero multiplier and cannot be reversed to one unique original value. Confirm whether the supplied percentage was measured from the original or from another base.
Frequently asked questions
How do I reverse a decrease?
Enter the decrease as a negative percentage, such as -20.
Why not subtract the percentage from the final value?
The original amount is the base of the forward change, so reversal divides by the multiplier.
Can a 100 percent decrease be reversed?
No. A zero final multiplier does not identify one original value.