Discount Calculator
Work out the final price after a discount, how much you’ll save, and what happens when multiple discounts are applied together.
How to Use the Discount Calculator
Our Discount Calculator instantly works out how much you’ll save and what you’ll actually pay after a percentage discount. Use the Single Discount tab for one-off sales and offers, or the Stacked Discounts tab when two or more discounts apply one after another, such as a seasonal sale price plus an extra loyalty coupon.
How Discount Percentages Work
A discount percentage is applied to the original price to work out how much is taken off. For example, a 25% discount on £80 means you save 25% of £80, which is £20, bringing the price down to £60. The formula is straightforward: discount amount = original price × (discount % ÷ 100), and final price = original price − discount amount.
| Original Price | Discount | You Save | Final Price |
|---|---|---|---|
| £20 | 10% | £2.00 | £18.00 |
| £50 | 20% | £10.00 | £40.00 |
| £80 | 25% | £20.00 | £60.00 |
| £120 | 30% | £36.00 | £84.00 |
| £200 | 50% | £100.00 | £100.00 |
How to Use the Discount Calculator
- Single Discount: Enter the original price and the discount percentage, or pick one of the quick preset buttons.
- Optionally enter a quantity to see the total price and total savings for more than one item.
- Results update automatically, showing the amount saved, the price after discount, and what percentage of the original price you’re paying.
- Stacked Discounts: Switch tabs, enter the original price, then add each discount in the order it’s applied.
- Click Calculate Stacked Discounts to see the final price, the total saved, and a step-by-step breakdown.
Why Stacked Discounts Don’t Simply Add Up
When two discounts are applied one after another, they are not additive. A 20% discount followed by an extra 10% off does not equal 30% off overall, because the second discount is calculated on the already-reduced price, not the original one. For example, £100 with 20% off becomes £80. Taking a further 10% off £80 saves £8, not £10, bringing the final price to £72. That’s an effective discount of 28%, not 30%. Our Stacked Discounts tab calculates this correctly by applying each discount to the running price, and shows you the true effective discount alongside a full breakdown.
Tips for Working Out Discounts
- Always check whether an “extra X% off” offer applies to the original price or the already-discounted sale price; most in-store and online stacked offers apply to the reduced price.
- When comparing two different-sized discounts on different items, compare the final price and the amount saved, not just the headline percentage.
- This calculator doesn’t apply multi-buy promotions (e.g. “3 for the price of 2”) automatically. To check the saving, work out the normal total price for all the items, then compare it with the promotional price — the difference is your total saving.
- Remember that a discount reduces the price you pay, but if the item is subject to VAT, the VAT is normally calculated on the discounted price, not the original price.
Frequently Asked Questions
How do you calculate a discount percentage?
Multiply the original price by the discount percentage divided by 100 to find the amount saved, then subtract that from the original price to get the final price. For example, a 20% discount on £50 saves £10, giving a final price of £40.
How do stacked or multiple discounts work?
Each discount is applied to the price remaining after the previous discount, not to the original price. This means stacked discounts always add up to less than the sum of the individual percentages. Two 20% discounts stacked together give an effective discount of 36%, not 40%.
What is the difference between a discount and a markdown?
The terms are generally used interchangeably in retail. Both refer to a reduction from the original or list price, usually expressed as a percentage or a fixed amount off.
Is VAT calculated before or after a discount?
VAT is normally calculated on the discounted price, not the original price. If a retailer offers 20% off a £120 item (VAT inclusive), the discount is applied first to bring the price to £96, and that £96 already includes VAT at the applicable rate.
How do I work out the original price from a sale price?
Divide the sale price by (1 minus the discount as a decimal). For example, if an item costs £60 after a 25% discount, divide £60 by 0.75 to get an original price of £80.
Can I calculate a discount for multiple items at once?
Yes, enter a quantity in the Single Discount tab to see the total price and total savings across all items, in addition to the per-item figures.