Reverse a percent increase or decrease to find the original amount.
Also known as: find original value before percentage change calculator, reverse percentage calculator, original price before 20 percent discount, find original value before percentage change, percentages math, percentages find original value before percentage change
Results update when you click Calculate.
Original value
100.00
Original = 120.00 / (1 + 20.00%)
Change amount
20.00
Percent change
20.00%
Reverse a percent increase or decrease to find the original amount. After increase: original = new ÷ (1 + p). After decrease: original = new ÷ (1 − p).
After increase: original = new ÷ (1 + p). After decrease: original = new ÷ (1 − p).
$120 after a 20% increase → original was $100.
Use “After decrease” when the new price reflects a markdown.