Discount Calculator
Find the sale price or work back to the original.
How to use
- 1 Choose "Apply discount" to find the sale price, or "Find original" to reverse one.
- 2 Enter the price — the original in apply mode, the sale price in reverse mode.
- 3 Enter the discount percentage.
- 4 Read off the saving and final price, or the recovered original price.
About Discount Calculator
The Discount Calculator handles the two everyday questions about a markdown: what does an item cost after a percentage off, and what was it before the discount was applied.
In apply mode, enter the original price and the percent off to see how much you save and the final price you pay.
In reverse mode, enter the sale price and the discount that was applied to recover the original list price.
Working out a discount in your head is fine for a round 10% or 50%, but odd percentages and prices with awkward decimals invite mistakes — and shops often advertise the saving without showing the final number, or the final number without the saving.
This tool removes the guesswork on both sides of the calculation.
The reverse mode is especially handy for checking whether a "was £X, now £Y" claim is genuine, or for reconstructing a pre-tax list price from a receipt.
Discounts are capped at sensible bounds — you cannot take more than 100% off, and a 100% reduction cannot be reversed because the original would be unknowable.
Everything is rounded to two decimal places and runs entirely in your browser.
FAQ
How does reverse mode work?
Given a sale price and the discount that was applied, it divides by one minus the discount fraction to recover the original list price — the number the markdown started from.
Why can I not reverse a 100% discount?
A 100% discount makes the sale price zero regardless of the original, so there is no way to work backwards to a single original price. Reverse mode therefore accepts discounts below 100%.