Discount Calculator
Work out the sale price after one discount or several stacked, the percent off between two prices, or the original price. Free, no sign-up, in your browser.
Sale price after a discount
Final price: 80 You save: 20
Find the discount %
Discount: 20%
Find the original price
Original price: 100 You save: 30
🔒 Calculated in your browser — nothing is uploaded. Plain numbers, no currency.
All three directions of the same sum
A discount has three questions and this page answers all of them without sending you anywhere else. Enter an original price and a percentage to see the sale price and what you save. Enter an original and a sale price to get the percentage between them. Or enter what you paid and the percentage that was advertised, and the third section works back to the list price — the question anybody standing in front of a ticket saying 70, was 30% off, is actually asking.
Stacked discounts, and why they are less than they look
Extra percentages typed into the second box are applied one after another to the running price, which is how stacked coupons actually work. 20% and then a further 10% is 28% off, not 30%, because the second coupon comes off a price the first one has already reduced. The page shows the effective discount so the difference is visible rather than assumed.
What it costs at the till
Set how many you are buying and a tax rate and the page adds a subtotal, the tax and the total to pay, in that order: every discount first, then the quantity, then tax on the discounted amount — the order shops actually ring it up in, and the one that gives the smaller number. Those lines stay hidden while you are buying one of something with no tax, so the simple case stays simple. Everything is plain numbers with no currency, so read the results in whatever units you entered; displayed figures are rounded to two decimals while the underlying math stays exact.
Frequently asked questions
How is the final price calculated?
Final price = original price − (original price × discount ÷ 100). The amount saved is original price × discount ÷ 100. Extra percentages are then applied one at a time to the running price rather than added together.
It says 70 and 30% off — what was the original price?
That is the third section: original = paid ÷ (1 − discount ÷ 100), so 70 at 30% off was 100. At 100% off or more there is no single answer, because every list price ends at the same place, and the page says so rather than showing a number.
How do I find the discount percentage from two prices?
Use the second section. Discount % = (original − final) ÷ original × 100. If the original price is zero the percentage is undefined, so the tool shows a short notice instead.
Why is 20% off then 10% off not 30% off?
Because the second discount comes off a price the first one already reduced. 100 becomes 80, and 10% of 80 is 8, so you pay 72 — 28% off in total. The effective discount line spells this out whenever you stack percentages.
Does it handle quantity and tax?
Yes. Fill in how many and a tax rate and you get a subtotal, the tax and the total to pay. Discounts come off first, then the quantity multiplies, then tax is added to the discounted amount.
Is anything uploaded to a server?
No. All calculations run entirely in your browser using JavaScript. Nothing you type is sent anywhere or stored.