Discount Calculator

A discount looks simple until a second one is stacked on top, at which point intuition often fails. Two discounts of twenty-five per cent do not make fifty per cent off. They make forty-three and three-quarters per cent, because the second discount applies to the already-reduced price, not the original.

That is the key insight of discount maths: percentages multiply, they do not add. The result is always slightly less generous than the sum of the parts suggests. The same logic works against you with successive price rises, where the effect compounds upward instead.

Working out the sale price is just a subtraction once you know the discount. Multiply the price by one minus the discount rate to get what you pay, and subtract to see the saving. Doing it in your head is easy for round numbers, which is why so many sales use twenty, twenty-five and fifty per cent rather than awkward figures.

The place people lose money is the comparison. A "was" price that never existed, or a discount applied to an inflated original, can make a deal look better than it is. The only meaningful test is the final price against what the same item costs elsewhere. A twenty per cent discount off a price twenty per cent above the market is no discount at all.

Sales tax usually applies to the discounted price, not the original, so tax should be calculated after the discount. It also nudges the final cost upward in a way that can quietly erase the benefit of a small discount.

Use this calculator to see the real, after-tax price and the true combined discount before you decide. It is a straightforward arithmetic tool with no fine print; the fine print lives in the shop's terms, which are worth reading.

This calculator returns estimates for general information only. It is not financial, investment, tax or legal advice, and it cannot replace guidance from a qualified professional who knows your circumstances. Figures such as loan payments, investment growth and retirement projections are simplified models based on the inputs and assumptions you provide, not guarantees of future results.