Calculate the sale price after a percentage off, with optional tax and stacked discounts.
A discount reduces the original price by a percentage or fixed dollar amount. For percentage discounts, multiply the original price by the discount rate and subtract the result from the original price. A 25% discount on a $80 item removes $20, leaving a sale price of $60. This calculator handles single discounts, stacked (double) discounts, and shows the effective total savings rate.
Stacked discounts are applied sequentially, not additively. A 20% discount followed by an additional 10% discount does not equal 30% off. The first discount reduces a $100 item to $80, and the second discount takes 10% off $80 (not $100), yielding $72. The effective discount is 28%, not 30%. The gap between the additive and actual discount grows as the individual percentages increase.
Retailers use several discount structures: percentage off (25% off), dollar amount off ($15 off), buy-one-get-one (BOGO), and tiered discounts (spend $100 get 10% off, spend $200 get 20% off). To compare these, convert everything to a percentage of the original price. A $15 coupon on a $75 item is a 20% discount. A BOGO deal on a $40 item is effectively 50% off per unit if you want both items, or 0% off if you only need one.
Tiered discounts incentivize spending more. If 10% applies at $100 and 20% at $200, you save $10 at the $100 level and $40 at the $200 level. But spending an extra $100 to save an extra $30 only makes sense if you actually need $200 worth of goods. The calculator helps you see the actual dollar savings at each level so you can decide whether spending up to the next tier is worthwhile.
In most U.S. states, sales tax is applied after the discount. If a $100 item is 20% off in a state with 7% sales tax, you pay $80 plus $5.60 tax for a total of $85.60. A few states or localities calculate tax on the original price before the discount, though this is uncommon. Enter your local sales tax rate in the calculator to see the true out-of-pocket cost. The Sales Tax Calculator has state-specific rates.
Retailers use specific pricing psychology to make discounts feel larger. The "rule of 100" states that for items under $100, a percentage discount feels larger (20% off $50 = "save 20%!"), while for items over $100, a dollar amount feels larger ($100 off $500 = "save $100!"). Anchoring bias means that showing the original price alongside the sale price makes the discount feel more significant. "Buy one get one 50% off" sounds better than "25% off everything" despite being equivalent. Flash sales and countdown timers exploit urgency bias. Coupons and promo codes trigger the "sunk cost" effect, making purchases feel like deals even when the pre-discount price was inflated. The best defense is calculating the actual dollar savings and asking whether you would buy the item at the sale price without knowing the original.