Do stacked discounts add up?

No. Twenty per cent then ten per cent is twenty-eight per cent off, because the second applies to the reduced price. Fifty then fifty is seventy-five per cent off, not a hundred.

How do I set a list price to hit a target after discount?

Divide the target by one minus the discount rate. For a target of 400 at twenty per cent off, the list price is 400 divided by 0.8, which is 500 — not 480.

What is buy-one-get-one worth as a percentage?

Fifty per cent off if you genuinely wanted both, and nothing at all if you did not. Three-for-two is a third off on the same condition. The arithmetic is straightforward; whether you needed the second item is the actual question.

Does this handle tax?

Not directly — it works on the price you give it. Use the GST calculator for the tax component, being careful about whether the price you started with was inclusive or exclusive.

Discount Calculator

Final price, money saved, and stacked discounts done right.

Everything runs inside your browser. Your files never leave your device.

Result

The result appears here as you type.

Ask about Discount Calculator

Questions about what this tool does, which option to pick, or what it can and cannot handle.

The question you type here is sent to an AI provider to be answered — your files and whatever you put in the tool above are not, and the assistant cannot see them. Answers are generated and can be wrong. The tool itself is not guessing: it runs deterministic code on your device.

About the Discount Calculator

Working out what a discount actually saves takes a moment, and shops rely on that moment. This calculates the final price and the amount saved from an original price and a discount, and handles the stacked cases that are genuinely hard to do in your head.

Successive discounts are the case worth understanding. Twenty per cent off followed by a further ten per cent is not thirty per cent off. The second reduction applies to the already-reduced price, so the combined effect is twenty-eight per cent. That gap widens as the numbers grow: fifty and then fifty is seventy-five per cent off, not a hundred, which is obvious once stated and is exactly how such offers are meant to be read quickly and misread.

Working backwards is the calculation that catches out anyone pricing something. To make a fifty rupee margin on an item you sell at a twenty per cent discount, the list price is not the target plus twenty per cent — it is the target divided by 0.8. Adding a percentage and removing it are not inverse operations, and the difference grows with the rate.

The other figure worth having is the effective discount on a bundle. Buy-one-get-one is fifty per cent off if you wanted both items and zero per cent off if you did not, and a three-for-two is a third off on the same terms. The calculator can tell you the rate; only you can say whether you needed the second one.

The most useful discount question is usually the total spend rather than the percentage. Thirty per cent off a thing you do not need is a hundred per cent of a wasted amount.

How to use it

1Enter the original price and the discount percentage.
2Read the final price and the amount saved.
3Apply stacked discounts in sequence rather than adding them together.
4To work backwards from a target price, divide by one minus the discount rather than adding the percentage on.

Questions

Do stacked discounts add up?: No. Twenty per cent then ten per cent is twenty-eight per cent off, because the second applies to the reduced price. Fifty then fifty is seventy-five per cent off, not a hundred.
How do I set a list price to hit a target after discount?: Divide the target by one minus the discount rate. For a target of 400 at twenty per cent off, the list price is 400 divided by 0.8, which is 500 — not 480.
What is buy-one-get-one worth as a percentage?: Fifty per cent off if you genuinely wanted both, and nothing at all if you did not. Three-for-two is a third off on the same condition. The arithmetic is straightforward; whether you needed the second item is the actual question.
Does this handle tax?: Not directly — it works on the price you give it. Use the GST calculator for the tax component, being careful about whether the price you started with was inclusive or exclusive.