Stacked Discount Calculator
Apply multiple sequential discounts to a price and see the final amount, step by step, plus the effective single discount. Shows why stacked percentages don't simply add. Runs in your browser.
Final price $72.00
- −20% on $100.00$80.00
- −10% on $80.00$72.00
Note: stacked discounts compound — 20% + 10% is not 30% off. Each discount applies to the already-reduced price.
About this tool
Stores love to stack offers — '20% off, plus an extra 10% at checkout' — and shoppers routinely overestimate the savings by adding the percentages. This calculator applies each discount in sequence to the running price and shows the true result. The key insight it makes concrete: percentages compound, they do not add. A 20% discount followed by 10% is not 30% off; the 10% applies to the already-reduced price, giving 0.80 × 0.90 = 0.72, an effective 28% off. The tool lists each step, the amount you save, and the equivalent single discount, so you can see exactly how the stack resolves and compare deals honestly (a flat 25% can beat '20% + 10%'). It supports any number of stacked percentage discounts. For pure percentage discounts the order does not change the final price, but the step-by-step view still clarifies the math. Everything is exact and runs in your browser.
How to use it
- Enter the original price.
- Add each percentage discount in the order it applies.
- Read the final price, total savings, and effective single discount.
- Compare against a single flat discount to find the better deal.
Frequently asked questions
- Is 20% off then 10% off the same as 30% off?
- No. The second discount applies to the already-reduced price, so 20% then 10% is 0.80 × 0.90 = 0.72, i.e. 28% off — not 30%. Stacked percentages always total less than their sum.
- How is the effective single discount calculated?
- It is 1 minus the product of all the (1 − discount) factors, as a percentage. For 20% and 10%: 1 − (0.80 × 0.90) = 0.28, or 28%. That is the single discount equivalent to the whole stack.
- Does the order of discounts matter?
- For pure percentage discounts, no — multiplication is commutative, so 20% then 10% equals 10% then 20%. Order only matters when you mix percentage discounts with fixed-dollar amounts or apply tax in between, which changes the base.
- Why do stores stack discounts instead of one big one?
- Stacking sounds more generous than it is — "20% + 10%" feels like 30% but is 28%. It also lets retailers combine a base sale with a coupon or loyalty offer. This tool reveals the real effective discount so you can compare.
- Can I compare a stack against a flat discount?
- Yes — read the "effective single discount." If a competitor offers a flat 25% and your stack computes to 28%, the stack wins; if it computes to 24%, the flat 25% is better.
- Is anything uploaded?
- No. All calculation runs in your browser with no network request.