Discount Calculator

Five modes for every shopping scenario. Stack coupons, reverse-engineer original prices, and queue multiple items to see your total savings.

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Stacked discounts apply one after another. 20% off then 10% off is not 30% off, it is 28% off.

Returns the discount percentage that was applied.

%

Returns the original price before the discount was applied.

A flat money-off coupon. Use this for fixed-value vouchers.

Final price
. . .
Enter values to calculate

How to use

  1. Pick a calculation mode at the top.
  2. Enter the values; the final price and savings appear instantly.
  3. Click Add to list to queue items and see combined totals.
  4. Use CSV to export your list, or Copy for a single result.
  5. Tax, when enabled, is applied to the discounted price like normal retail pricing.

Why stacked discounts are not additive

If a 100 item is 20% off, you pay 80. An extra 10% off the 80 takes off 8, not 10. Final price is 72, an effective 28% discount, not 30%.

Frequently asked questions

How do stacked discounts work?

Each discount applies in turn to the running total. Two consecutive 20% offers do not equal 40% off; together they remove only 36% of the original price, because the second 20% applies to the already-reduced amount.

Does the calculator include tax?

Yes if you enable the tax option. It defaults to a tax-inclusive view for everyday shopping comparisons but can be toggled off.

What is the effective discount percentage?

It is the total savings divided by the original price, expressed as a percent. It is the single most useful number when comparing two deals that combine different stacked offers.

Can I print or share a price comparison?

Yes. Use the copy button to grab a plain-text breakdown, or screenshot the breakdown card to share quickly in chat.

How discount math actually works

A single discount is simple: a 30% reduction on a 80 EUR jacket takes off 24 EUR and leaves 56 EUR. Where people lose money is stacked discounts. "30% off, plus an extra 20% off at checkout" is not 50% off. The second discount applies to the already reduced price, so the combined effect is 1 - (0.70 x 0.80) = 44% off, not 50%. On a 100 EUR item that difference is 6 EUR, and across a full cart it adds up quickly.

The reverse calculation trips people up even more. If a price after a 25% discount is 60 EUR, the original was not 60 + 25% = 75 EUR. It was 60 / 0.75 = 80 EUR. Dividing by (1 - discount) is the only correct way to recover an original price, and it is exactly what this calculator does in reverse mode.

Reading retail pricing critically

Retailers use discount framing deliberately. "Up to 70% off" usually means a handful of items at 70% and most of the rack at 10-20%. "Was 199, now 99" is only meaningful if the item genuinely sold at 199 recently. A calculator will not tell you whether a reference price is honest, but it will tell you the real unit cost, which is the number worth comparing across shops.

Quick rules worth memorising

  • Two stacked discounts of a% and b% combine to a + b - (a x b / 100). So 20% + 20% = 36%, not 40%.
  • A 50% discount followed by a 50% markup does not return to the original price. 100 down to 50, up to 75.
  • Percent off and percent of are complements: 35% off means you pay 65% of the price.
  • For mental math, 10% is one decimal shift. 15% of 84 = 8.4 + 4.2 = 12.6.
  • When comparing "3 for 2" against a flat percentage, convert both to price per unit before deciding.

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