How to use the discount calculator
Enter the original price and the discount percentage. If the store offers an additional discount on top (for example "extra 10% off sale items"), enter it in the second box. Add your local sales tax rate if you want the price you will actually pay at the till.
Discount formula
Sale price = Price × (1 − Discount ÷ 100)
For stacked discounts, apply each one in turn:
Final = Price × (1 − d₁/100) × (1 − d₂/100)
Example
A jacket costs 120 and is 30% off, with an extra 15% at checkout:
- After 30% off: 120 × 0.70 = 84
- After the extra 15%: 84 × 0.85 = 71.40
- Total savings: 48.60, which is a 40.5% total discount
Shopping tips
- Compare the final price, not the size of the percentage. "40% off" a marked-up price can still cost more than a regular price elsewhere.
- Stacked discounts are always worth slightly less than adding the percentages together.
Frequently asked questions
How do I calculate a discount?
Multiply the original price by the discount percentage and divide by 100 to get the savings, then subtract the savings from the original price. 25% off 80 saves 20, so the sale price is 60.
Is 20% off plus an extra 10% off the same as 30% off?
No. The extra 10% applies to the already-reduced price. 100 with 20% off is 80, and 10% off 80 is 72 — a total discount of 28%, not 30%.
Is tax added before or after the discount?
In most places sales tax is charged on the discounted price, which is how this calculator works.