Free Discount Calculator — Percent Off and Sale Price

The basic discount formula is sale price = original price × (1 − discount% ÷ 100). Divide the discount percentage by 100 to convert it to a decimal, subtract from 1, then multiply by the original price. For example, 25% off $80 is $80 × 0.75 = $60, and your savings are $80 × 0.25 = $20.

To find the discount percentage when you already know both prices, subtract the sale price from the original, divide by the original, then multiply by 100. If an item was $89.99 and is now $71.99, the discount is ((89.99 − 71.99) ÷ 89.99) × 100 = 20%.

Sales tax is always applied to the post-discount price in most US states and international jurisdictions — tax is charged on what you actually pay, not the original retail price. So a 20% discount on a $100 item taxed at 8.5% means you pay tax on $80, giving a final price of $86.80 — not tax on the original $100.