Discount Stacking Calculator

This calculator works out the final price when several discounts are applied one after another in New Zealand, and reveals the true effective discount, which is almost always less than the headline percentages added together. Shops love to advertise things like an extra ten percent off already-reduced stock, or a member discount on top of a sale price, and it is tempting to add the numbers up in your head, but stacked discounts do not work that way. Each discount applies to the price after the previous one, so they multiply rather than add: twenty percent off followed by ten percent off is not thirty percent off, because the ten percent comes off the already-reduced eighty percent price, leaving you with twenty-eight percent off in total. This catches people out and makes a deal look better than it is. You enter the original price and up to three sequential discount percentages, and the calculator returns the final price, the total amount saved, and the single effective discount that those stacked percentages actually add up to. Use it to see the real saving on a stacked offer, to compare it against a flat discount elsewhere, and to avoid overestimating a bargain. For percentage discounts the order does not change the final price. A handy reality check on stacked deals.

Stacked discounts multiply, not add, so the effective discount is less than the percentages summed. Order does not change the result for percentages.