Discount Calculator

A single discount is easy to compute in your head; stacked discounts ("20% off, plus an extra 10%") are where most people get the arithmetic wrong — the second discount applies to the already-discounted price, not the original, so 20% + 10% is not a flat 30% off. This calculator gets the sequencing right and shows you the true effective discount.

Enter the original price and your first discount, and optionally a second discount that stacks on top of the first. The calculator applies them in sequence — first discount off the original price, second discount off that reduced price — and reports both the final price and the true effective discount percentage, which is always slightly less than simply adding the two percentages together.

This matters for retailers designing promotions (know exactly what margin you're giving away before advertising "up to 30% off"), and for shoppers evaluating whether a stacked coupon deal is actually as good as it sounds. A 20% + 10% stack, for instance, works out to a 28% effective discount, not 30% — a difference worth knowing on a large purchase.

If you're pricing a sale, check the final margin left after the discount against your product cost, not just against the original price — a generous-looking discount can quietly erase your entire profit on a low-margin item, something the margin calculator makes easy to check once you know the discounted selling price.