Discount Calculator
Final price after one or two discounts, plus tax.
A second discount applies to the already-reduced price.
Added after the discount, which is how checkout works.
You pay
$90.00
25.0% off the original
How the Discount Calculator works
Discounts stack multiplicatively, not additively — 20% off then an extra 10% off is 28% off, not 30%. This calculator handles stacked discounts and adds sales tax so you know what the register will actually charge.
Not financial advice. This calculator is for planning and illustration, not financial advice. Real products carry fees, taxes, and terms it does not model. Confirm figures with your lender or a qualified adviser before committing.
Frequently asked questions
How do I calculate a percentage discount?
Sale price = original price × (1 − discount ÷ 100). For 25% off a $80 item: 80 × 0.75 = $60, a saving of $20.
How do stacked discounts work?
The second discount applies to the already-reduced price. 30% off then 20% off gives 0.70 × 0.80 = 0.56, so 44% off in total, not 50%. Retailers rely on this looking better than it is.
Is tax applied before or after the discount?
After. Sales tax is charged on the discounted price you actually pay, which is why a discount also shrinks the tax you owe. This calculator applies tax last, matching standard checkout behaviour.
How do I work out the original price from a sale price?
Divide by (1 − discount ÷ 100). An item marked $45 after 40% off was originally 45 ÷ 0.60 = $75.