How does the Discount Calculator work?
Final price = price × (1 − discount). Your saving is the difference from the original price.
Background & details
Reading the result properly
The calculator shows the final price and your saving in pounds. For buying decisions the money saved often matters more than the percentage: 10 % off a car is worth more than 50 % off a cup of coffee. Look at both – the percent shows how attractive the deal looks, the cash amount shows the real effect on your budget.
What counts as a good discount
In retail, 10–20 % are normal seasonal markdowns, 30–50 % signal a genuine clearance, and anything above 60 % is usually old stock or a loss-leader. Beware inflated reference prices: if the "original price" is pushed up and then struck through, the discount looks bigger than it is. Checking the price history (via a comparison site) exposes this quickly.
Common mistakes
- Adding instead of multiplying: 20 % plus 10 % is not 30 % but 28 % off, because the second discount only applies to the already-reduced price.
- Reversing it wrongly: if the reduced price is £80 after 20 % off, the original was 80 ÷ 0.8 = £100, not 80 × 1.2 = £96.
- Forgetting shipping: a big discount with pricey delivery can cost more than a modest discount with free shipping.
Combining several discounts correctly
When you stack two discounts you multiply the remaining fractions. 20 % and 10 % means: first times 0.8, then times 0.9 – leaving 0.72 of the original, which is 28 % off in total. The order makes no difference to the result (0.8 × 0.9 = 0.9 × 0.8). It only matters when a fixed-amount voucher is involved: a £10 voucher applied before a 20 % sale gives a different total than after it. Rule of thumb: never lump percentage discounts and fixed amounts together – work through them step by step. For a quick estimate in the shop, two moderate discounts combined almost always land a little below their sum, never above it.
Practical tips
When haggling, think in cash: ask for a specific amount off rather than a percentage, it is more concrete. When stacking offers (a voucher plus a sale), check the order – some shops apply the voucher before the sale price, others after, which changes the final total.
When this tool is not the right one: tiered volume discounts, early-payment terms that depend on a deadline rather than the list price, or discounts quoted on the pre-tax net amount. Early-payment terms, for example, only apply if you pay within the window, which is a different logic from a permanent price cut.