Discount Calculator
Calculate final price after a discount, the savings amount, or reverse-engineer the discount rate from two prices.
Final Price
$90.00
You Save
$30.00
25% off
Original
$120.00
before discount
Savings Breakdown
Discounts: stack rules, outlet math, and reversals
Model “% off” and “take two prices, infer % off” in one place—useful for retail audits and e-commerce QA. Chain with the percentage calculator for YoY price deltas.
Promotions that apply in sequence (20% then $10 off) are not commutative; enter final shelf price when in doubt.
Related tools
These free tools pair well with this page — open them in a new tab to finish your workflow.
Frequently Asked Questions
How is the discounted price calculated?
Discounted price = original price × (1 - discount% / 100). For example, a £80 item with a 25% discount: £80 × 0.75 = £60. The amount saved is £80 - £60 = £20.
How do I calculate the original price from a sale price?
If you know the final price and the discount percentage, the original price = final price / (1 - discount% / 100). For example, £60 at a 25% discount means the original was £60 / 0.75 = £80.
What is the difference between a percentage discount and a fixed amount discount?
A percentage discount scales with the item price — a 20% discount on a £200 item saves more (£40) than on a £50 item (£10). A fixed amount discount (e.g. £10 off) saves the same regardless of price.
How do I calculate a discount after tax?
It depends on the order of operations. Discount before tax: apply the discount, then add tax. Discount after tax: add tax first, then apply the discount. These give different final prices. Most retail discounts are applied before tax.
What is a stackable discount?
Stackable discounts are applied sequentially, not added together. A 20% discount followed by a 10% discount is not 30% off — it is 1 - (0.8 × 0.9) = 28% off. Always multiply the remaining fractions, not add the percentages.
What does 'buy one get one X% off' mean?
'Buy one get one 50% off' means you pay full price for one item and 50% for the second. If each item costs £10, you pay £10 + £5 = £15 for two, an effective 25% discount on the pair.
Is a 50% discount the same as half price?
Yes. A 50% discount means you pay 50% of the original price, which is exactly half price. A 100% discount would be free.