Discount Calculator
Work out the sale price and how much you save — with stacked discounts (e.g. 20% off then an extra 10%) and sales tax.
For information and education only — not financial advice. Results are estimates based on the numbers you enter; check important decisions with a qualified professional.
How to use
- 1Enter the original price and the discount percentage.
- 2Add an extra discount or sales tax if they apply.
How it's calculated
Sale price = price × (1 − d₁) × (1 − d₂). Stacked discounts multiply, so 20% then 10% off is 28% off in total — not 30%.
Frequently asked questions
Is 20% off plus 10% off the same as 30% off?
No. The second discount applies to the already-reduced price, so the total is 28% off. Our calculator shows the combined rate.
Is tax charged before or after the discount?
In most places sales tax or VAT is charged on the discounted price, which is how we calculate it.
How do I work out a discount in my head?
Find 10% by moving the decimal point one place left, then multiply. 30% off $80: 10% is $8, so 30% is $24 and you pay $56.