Calculate the final sale price and total savings after applying one or two successive discounts.
A discount calculator works out the final sale price and total savings after applying one or two successive percentage discounts to an original price. This is useful for working out the actual price during a sale, especially when an "extra" discount is applied on top of an already-reduced price — a common scenario that often catches people out, since successive discounts don't simply add together.
Each discount is applied to the price remaining after the previous discount — not to the original price. This means two discounts don't simply add together: a 20% discount followed by a 10% discount results in a total discount of less than 30%, because the second discount applies to an already-reduced amount.
Formula: Price After First Discount = Original Price × (1 − First Discount % ÷ 100). Final Price = Price After First Discount × (1 − Additional Discount % ÷ 100). Total Savings = Original Price − Final Price. Total Discount % = (Total Savings ÷ Original Price) × 100.
Example: A £100 item with a 20% discount, followed by an additional 10% discount, first reduces to £80 (20% off £100), then to £72 (10% off £80) — a total saving of £28, which is a 28% overall discount, not 30%. (Note: this example is for illustration purposes only.)
Successive ("stacked") discounts are common during sales — for example, "20% off, plus an extra 10% off in the final reduction" — and the maths above shows why the combined discount is always less than simply adding the two percentages. UK pricing rules generally require that "was/now" or "sale" pricing reflects a genuine prior price (a product shouldn't be marked up shortly before a sale just to make the discount look bigger), so a stated discount percentage should reflect a real saving against a recent genuine selling price. If you're VAT-registered and applying discounts to prices for accounting purposes, make sure you're clear on whether the price you're discounting includes or excludes VAT, as this affects both the discount calculation and the VAT due on the final sale.
Because the second discount is applied to the price remaining after the first discount, not to the original price. A 20% discount followed by a 10% discount means the 10% is calculated on the already-reduced (80%) price, resulting in a total discount of 28%, not 30%.
Mathematically, no — applying a 20% discount then a 10% discount gives the same final price as applying the 10% discount first then the 20% discount, because multiplication is commutative. The total discount percentage will be the same either way.
No. This calculator applies percentage discounts to whatever price you enter, without separately calculating VAT. If you need to know the VAT on a discounted price, use this calculator to find the final price first, then use the VAT Calculator to add or extract VAT from that figure.
It's the overall percentage saving compared to the original price, accounting for both discounts being applied successively. This is always less than the sum of the two individual discount percentages (unless one of them is 0%), as explained above.
This calculator is set up for discounts up to 90% for typical use, but the underlying formula works for any percentage between 0% and 100%. A 100% discount would result in a final price of £0.
Yes, broadly. UK pricing practices are subject to consumer protection rules intended to ensure that reference prices used in sales (such as a crossed-out "was" price) reflect genuine prior prices, rather than artificially inflated figures used to make a discount appear larger than it really is.
Disclaimer: The information and figures provided on this page are for educational and illustrative purposes only. This calculator performs a mathematical calculation based on the percentages and price you enter, and does not verify the accuracy of any advertised discount or sale price. Always check the actual price at checkout, as advertised discounts may be subject to terms and conditions, exclusions, or other adjustments.