Discount Calculator

How Discount Calculator works

See what you pay and what you save with one or two stacked percentage discounts. Everything happens inside this page: the tool reads your input, runs the calculation or conversion locally, and hands the result back to you. Nothing is transmitted, because there is no backend to transmit it to.

That design choice is deliberate. Most free tool sites upload your files to a server, process them there, and quietly keep a copy. Toolcin cannot do that — the site is a set of static files. If your connection dropped the moment the page finished loading, every tool would still work.

One discount, or two stacked

Enter the price and a percentage, and the tool shows the amount saved and what you pay. Add a second percentage and it applies that to the already-discounted price — which is how stacked offers actually work in a shop.

This is the arithmetic that catches people out: 20% then 10% is not 30%. On 1,000, the first takes it to 800, the second takes 80 more, and you pay 720 — a 28% total discount.

Why the order does not matter

Applying 20% then 10% gives the same result as 10% then 20%, because multiplication is commutative: 1,000 × 0.8 × 0.9 = 1,000 × 0.9 × 0.8. Shops sometimes imply otherwise; the arithmetic does not care.

What does matter is whether the second discount applies to the original price or the reduced one. “Extra 10% off the sale price” is the stacked case; “10% off full price” is not, and the two produce different totals.

Tax after discount

Sales tax is normally calculated on the discounted price, not the original. If a bill shows tax on the pre-discount amount and a discount applied afterwards, the totals will not match a simple percentage calculation — that is a bookkeeping order, not an error in your maths.

The tool works in the currency you type and does no conversion.

Good to know

• Works offline once loaded, including on flights and in locked-down networks.
• No file size limit beyond your device's own memory.
• Free to use, with no account and no usage counter.
• Results are produced locally, so they are not logged or shared with anyone.

Questions