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Discount Calculator

Calculate sale prices, stacked discounts, reverse percentages, bundle deals and sales tax with cent rounding.

Discount Calculator: Uses integer cents and exact rational discount factors. Stacks round once at the end, with tax rounded separately. Tax before discount means tax on the original total, added to the sale subtotal. Bundle comparisons assume identical items and an original price per item. Runs 100% locally in your browser with zero server file uploads.

Category
Home & family tools
Runs
In your browser
Cost
Free · no sign-up
Availability
Ready to use
Discount calculatorLocal processing

Runs entirely in your browser

Tax is based on the discounted total. This is a comparison; check the tax treatment that applies to your purchase.

Final total with tax$16.99
Savings before tax$3.0015% off
Price before tax$16.99Tax: $0.00

Prices use cents. Stacked discounts round once at the end; tax rounds separately. A displayed unit price may not multiply back to the exact bundle total.

Arithmetic and rounding

Discounted price = original price × (1 − percentage/100). Successive factors multiply; reverse percentage = (original − sale)/original × 100. Prices accept up to two decimals and round half up in cents. These are arithmetic comparisons, not jurisdiction-specific tax rules. Percentage explanation: https://openstax.org/books/prealgebra-2e/pages/6-1-understand-percent

Currency and deal comparisons

Currency formatting uses the page locale and Intl.NumberFormat; no exchange conversion is performed. Bundle unit price = sale total / received items. Buy N get M assumes the free items have the same original price. Intl specification: https://tc39.es/ecma402/#numberformat-objects

How to use it

  1. Choose a discount mode and currency.
  2. Enter prices, discounts or item counts and the tax basis.
  3. Read the savings, effective discount and final total.

Privacy & limitations

Inputs stay in your browser. Nothing is uploaded.

Related tools

PercentageUnit PriceSales Tax

Frequently asked questions

Why is 20% then 10% only 28% off?

You pay 0.8 × 0.9 = 0.72 of the original price. The remaining 28% is saved. Order does not change this product; intermediate shop rounding can differ.

What does 8折 mean?

It means paying eight tenths of the price: 20% off. The calculator also accepts 8.5折 and 打8折. Chinese locales display the alternative notation.

What does buy N get M free mean?

Pay for N identical items and receive N + M items. The percentage saved is M divided by N + M, multiplied by 100.

Embed this tool

Free to use on any website. Paste the code where the tool should appear; the link under it lets readers open the full page.

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<p style="margin:4px 0 16px;font-size:13px"><a href="https://toea.com/discount-calculator">Discount Calculator</a> &middot; TOEA</p>
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Free tool · runs in your browser · no account required