How to use the Discount Calculator
- Enter the original price and the discount percentage.
- Add a sales tax rate if you want the final price with tax.
- Read the savings, the sale price and the final price.
The formulas
- Discount amount = price × discount ÷ 100
- Sale price = price − discount amount
- Final price = sale price + sale price × tax ÷ 100
Worked example
An item priced at 80 with 25% off saves 80 × 25 ÷ 100 = 20, so the sale price is 60. With 8% sales tax added to the sale price, the tax is 4.80 and the final price is 64.80.
Stacked discounts
Two discounts do not add up. 20% off followed by another 10% off is not 30% off: 100 becomes 80, then 72, which is 28% off in total. To check a stacked offer, apply one discount, then enter the new price and apply the next.
Tax and discount order
In most places tax is calculated on the discounted price, which is what this calculator assumes. Rules differ between regions and stores, so check your receipt.
Frequently asked questions
How do I calculate a discount?
Multiply the price by the discount percentage and divide by 100. Subtract the result from the price to get the sale price.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount ÷ 100). For example, 60 after 25% off came from 60 ÷ 0.75 = 80.
Is tax added before or after the discount?
Usually after: tax is charged on the reduced price. This calculator works that way.
Does the calculator work with any currency?
Yes. Results use the same currency as the price you enter.
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Last updated: November 6, 2026