| Original value | |
| Final value | |
| Difference | |
| Percentage change |
How to use this calculator
Select your currency at the top — it auto-detects from your location but you can switch it manually. Enter the final amount you know, choose whether it was a decrease or an increase, enter the percentage, and hit calculate.
How to find the original price before a discount
- Take the sale price (e.g. $85)
- Subtract the discount percentage from 100 (e.g. 100 - 15 = 85)
- Divide by 100 to get a decimal (e.g. 0.85)
- Divide the sale price by that decimal (e.g. $85 / 0.85 = $100)
The original price was $100. The 15% discount saved $15. The calculator handles this in one step.
Common uses for reverse percentage
Shopping is the most common scenario. You see an item for $60 in a 25% off sale and want to check if the original price was genuine. Divide $60 by 0.75 and you get $80. If you've seen that item at $80 before, the deal is real. If not, it's a manufactured discount.
The same logic applies to salary negotiations, VAT reverse calculations, and any situation where you know the result of a percentage change but need the starting point.