Optional. Applied to the already-discounted price, e.g. an extra 10% off at checkout.
Optional. Added after the discounts.
- Original price120.00
- After 25% off90.00
Results are estimates for general information only and are not financial advice. Rates, fees and taxes vary, so confirm important figures with your lender or a qualified adviser.
How to use the Discount Calculator
- 1Enter the original price before any discount.
- 2Enter the discount percentage, for example 25 for 25% off.
- 3Optionally enter an extra discount, which is applied to the already-reduced price.
- 4Optionally enter a sales tax rate to add tax after the discounts.
- 5Read the final price, the amount you save, the effective discount and the step-by-step breakdown.
How to calculate a discount
To find a sale price, multiply the original price by the percentage you still pay. A 25% discount means you pay 75% of the price, so the sale price is price × (1 − 25 ÷ 100). The amount you save is the original price minus the sale price, or simply price × discount ÷ 100.
For example, 25% off 120 gives 120 × 0.75 = 90, a saving of 30. If you want a refresher on the underlying arithmetic, our guide on how to calculate percentages walks through the common types of percentage question.
Stacked discounts are not added together
Shops often advertise offers such as "25% off, plus an extra 10% at checkout". It is tempting to add these to 35%, but the second discount applies to the already-reduced price, not the original. The combined discount is 1 − (1 − 0.25) × (1 − 0.10) = 0.325, or 32.5%.
Using the same 120 item: after 25% off it costs 90, and an extra 10% off 90 brings it to 81. You save 39, which is 32.5% of the original price. The order of the two discounts does not matter, because multiplication gives the same result either way. This calculator shows the effective discount so you can compare stacked offers with a single larger one.
Adding sales tax after the discount
In most places sales tax is charged on the price you actually pay, so it is added after discounts are taken off. With 8% sales tax, the 81 sale price becomes 81 × 1.08 = 87.48, of which 6.48 is tax. The calculator shows the price before tax and the tax amount separately so you can check your receipt.
If you need to work backwards from a tax-inclusive price, or the figure you have already includes VAT or GST, use our sales tax and VAT calculator, which can both add and remove tax.
Tips for judging a sale
A percentage off is only meaningful compared with the price you would normally pay, so check whether the original price is the usual selling price. Compare offers by final price rather than headline percentage: 30% off a 150 item (105) still costs more than 20% off a 120 item (96).
If you are deciding whether a purchase is worth the money, converting the cost into hours of work can help. Our salary to hourly calculator gives you your hourly rate for that comparison.
Learn more
Frequently asked questions
How do I work out the percentage discount from two prices?
Subtract the sale price from the original price, divide by the original price and multiply by 100. If an item drops from 80 to 60, the discount is (80 − 60) ÷ 80 × 100 = 25%. Our percentage calculator can also find percentage changes like this.
Is 20% off and then 20% off the same as 40% off?
No. Two 20% discounts give 1 − 0.8 × 0.8 = 0.36, a 36% discount in total. Stacked discounts are always slightly less than the sum of the percentages.
Should sales tax be calculated before or after the discount?
Usually after. Tax is normally charged on the actual selling price, so discounts reduce the tax too. Some coupons funded by manufacturers are treated differently in certain regions, so check local rules if the exact amount matters.
Can I leave the extra discount and tax fields empty?
Yes. Both are optional and are treated as zero when left blank, so the calculator works as a simple single-discount calculator.
Why does the effective discount differ from the numbers I typed?
The effective discount is the total saving as a percentage of the original price. With one discount it matches what you entered. With a stacked discount it is lower than the two percentages added together, because the second one applies to a smaller amount.