Discount Calculator
Find out exactly how much you save with our free discount calculator. Enter the original price and discount percentage to instantly see the sale price, total savings, and effective discount. Supports stacked discounts (e.g. 25% off plus an extra 10% off) and optional sales tax calculation.
Calculating discounts is straightforward: Final Price = Original Price x (1 - Discount / 100). For example, a $120 item at 25% off costs $120 x 0.75 = $90, saving you $30.
Stacked discounts are a common retail strategy where an additional percentage is taken off an already-discounted price. Important: stacked discounts are NOT additive. A 25% discount plus a 10% discount is NOT 35% off. Instead, the second discount applies to the already-reduced price. On a $120 item: first 25% off gives $90, then 10% off $90 gives $81. The effective discount is 32.5%, not 35%.
The general formula for stacked discounts is: Effective Discount = 1 - (1 - d1/100) x (1 - d2/100), where d1 and d2 are the discount percentages. The order of the discounts does not matter mathematically -- 25% then 10% gives the same result as 10% then 25%.
When sales tax applies, it is calculated on the discounted price, not the original price. This means discounts also reduce the tax you pay. A $120 item at 25% off with 8% tax: discounted price is $90, tax is $7.20, final price is $97.20. Without the discount, you would pay $129.60 (including tax), so the total savings is $32.40.