Discount Calculator
Work out the sale price after a percentage discount, or find the discount percentage from an original and a paid price.
Discount off the original price
Results update as you type.
Formula
Two short formulas — pick the tab for what you know:
- % off → sale price:
savings = original × (percent / 100), thensale = original − savings. - What % off?:
savings = original − sale, thenpercent = (savings / original) × 100.
When this calculator helps
A percentage off sounds simple until you are stood in a shop trying to do it in your head while a queue forms behind you. This calculator is for exactly those moments — working out what you will actually pay, and how much you are saving, the instant you see a '25% off' tag or a voucher code at checkout. It handles seasonal sales, clearance reductions, loyalty-card offers, student and staff discounts, and Black Friday or Boxing Day deals where the headline percentage is doing a lot of marketing work.
It is just as handy before you buy as at the till. Comparing two offers on the same item — one shop showing '30% off £90' against another showing 'now £65' — is much easier when both are reduced to a single pounds-and-pence figure. And because UK promotions love to stack ('extra 10% off sale prices this weekend'), it is worth knowing how to chain reductions properly so a deal that looks enormous turns out to be what it really is.
How to read your result
The calculator gives you two numbers: the sale price (what you hand over) and the amount saved (the difference from the original). The saving is the figure to sanity-check against the headline — a genuine 25% off £80 should show £20 saved and £60 to pay. If the saving looks smaller than you expected, the discount probably applies to a lower base than you assumed.
The big thing to get right is stacked offers. Two discounts never add up. A 20% reduction followed by an extra 10% off at the till is not 30% off — the second cut applies to the already-reduced £64, not the original £80, so you land at £57.60, a true saving of 28%. Successive percentages always multiply rather than sum, which is why a chain of generous-looking discounts saves less than the headline numbers added together suggest. Run each reduction through the calculator in turn to see the real running total.
A worked example
Suppose a winter coat is ticketed at £120 with a '40% off' sale sign, and you also have a loyalty voucher for a further 10% off sale items. Apply the 40% first: £120 becomes £72, a £48 saving. Now apply the 10% to that £72, not to the original £120 — you take off £7.20, leaving £64.80. Your total saving is £55.20, which is 46% off the original, not the 50% you might assume from adding 40 and 10. The coat that looked half price is actually a little dearer than half price, and the calculator makes that gap obvious before you commit.
Common mistakes to avoid
Most discount slip-ups come from how the percentages are combined and what base they apply to.
- Adding stacked percentages together — '20% then 10%' is 28% off, not 30%, because the second cut applies to the reduced price.
- Confusing '% off' with '% of' — 25% off means you pay 75% of the price, not 25% of it.
- Assuming the 'was' price was genuine; under UK pricing rules it should have been the real selling price for a meaningful period before the sale.
- Comparing two deals by their headline percentages rather than by the actual pound price you would pay.
UK pricing and VAT notes
The convenient thing about discounting in UK shops is that the price on the tag already includes VAT at 20% (or the reduced or zero rate where it applies, such as on most food and children's clothing). That means the discounted figure this calculator gives you is the real, all-in amount you pay at the till — there is no tax to add on afterwards. A £60 sale price is £60 in your hand, VAT and all.
The one place this differs is business-to-business buying, where quotes are often shown net of VAT. There you apply the discount to the net price first and then add VAT to the reduced net, so the percentage off and the tax are calculated in sequence. For everyday retail, though, you can trust the sale price here as the final cost — use the VAT calculator only if you are working from net B2B figures.
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Frequently asked questions
How do I work out a percentage discount?▾
Multiply the original price by the discount percentage and divide by 100 to get how much you save, then subtract that from the original. So a 25% discount on £80 saves you £20, leaving a sale price of £60. The calculator does this in one go on the % off → sale price tab.
How do I find the discount percentage if I only know what I paid?▾
Subtract the sale price from the original to get the saving, divide that by the original, then multiply by 100. £80 down to £60 is a £20 saving, divided by £80 = 0.25, so 25% off. Use the What % off? tab to do it without the arithmetic.
What does '50% off' actually mean on UK signage?▾
It means the price has been halved — the sale price is half the original. UK consumer-protection rules say a 'was/now' price has to be genuine: under the Chartered Trading Standards Institute's Pricing Practices Guide and the CMA's enforcement, the higher 'was' price should have been the actual selling price for a meaningful period (typically 28 days) before the discount, otherwise the comparison is misleading. The calculator just tells you the maths; whether the headline price was genuine is on the retailer.
Are stacked discounts the same as adding the percentages together?▾
No — and the difference matters. '20% off then an extra 10% off at checkout' is *not* 30% off; it's 20% off, then 10% off the discounted price, which works out to 28% off the original. Each discount applies to the running total, so stacking always gives a smaller saving than the sum of the percentages. This calculator does one discount at a time; chain it manually for stacked deals.
Should I apply VAT before or after the discount?▾
It depends on whether the prices on display are VAT-inclusive (which is standard in UK retail) or VAT-exclusive (more common in B2B). UK retail price tags include VAT, so the discount is calculated on the gross price you see — the percentage off applies to whatever's printed. For B2B quotes that show net prices, take the discount on the net first, then add VAT to the discounted net using the VAT calculator.