How to calculate a discount with sales tax

Take the discount off first, then add tax to the lower price. That is how most US stores ring up a sale. The Discount Calculator shows the sale price, what you save, and the total with tax.

Percent off

Sale price = price × (1 – percent off ÷ 100). An $80 item at 25% off is $80 × 0.75 = $60.00. You save $20.00. With 8.25% sales tax, tax is $4.95 and you pay $64.95.

Stacked discounts

“30% off, then an extra 10% at checkout” is not 40% off. The second discount applies to the reduced price: $120 × 0.70 × 0.90 = $75.60, which is 37% off in total.

Dollars off

$15 off a $49.99 item is $34.99 before tax.

Coupons and tax

Store discounts usually lower the taxable price. Manufacturer coupons can be taxed on the original price in some states. For the percentage math on its own, see the Percentage Calculator.