Reverse Percentage Calculator
Find the original price before a discount was applied. Enter the final price and discount percentage to reverse-calculate the original value.
How to Reverse-Calculate the Original Price
Subtract the discount from 100 to get the percentage you actually paid.
100 − 20 = 80%
Divide by 100.
80% → 0.80
Divide the price you paid by the decimal.
6,400 ÷ 0.80 = 8,000
Original Price = Final Price ÷ (1 − Discount% ÷ 100)
Worked Examples
You paid 6,400 after a 20% discount.
6,400 ÷ (1 − 0.20) = 6,400 ÷ 0.80 = 8,000
An item costs 1,100 including 10% tax. What was the pre-tax price?
1,100 ÷ (1 + 0.10) = 1,100 ÷ 1.10 = 1,000
You found a bag for 2,100 at 70% off.
2,100 ÷ (1 − 0.70) = 2,100 ÷ 0.30 = 7,000
A gym membership costs 4,250 after a 15% member discount.
4,250 ÷ (1 − 0.15) = 4,250 ÷ 0.85 = 5,000
Frequently Asked Questions
Why can't I reverse a 100% discount?
A 100% discount means the final price is zero regardless of the original price. Since any number times zero is zero, there is no unique original price to recover.
Can I use this for tax-inclusive prices?
Yes. If the price includes tax, enter the tax-inclusive price and the tax rate. The formula works the same way to find the pre-tax amount.
What if multiple discounts were applied?
You need to reverse each discount separately, starting with the last one applied. This calculator handles a single discount. Apply it once for each discount layer.
Is this the same as adding the discount back?
No. Adding 20% to 6,400 gives 7,680, not 8,000. You must divide, not add, because the discount was applied to the original price, not the final price.