Stacked discounts apply one price reduction after another. If a product is 20% off and a coupon takes another 10% off the reduced price, the total saving is 28%, not 30%. The second discount uses a smaller starting amount.
You can check each step with the Our Daily Tools Percentage Calculator. Use its add-or-subtract mode to apply the first reduction, then use the resulting price for the next one. This guide shows the successive discount formula and five examples you can follow before comparing offers.
How stacked discounts work
A percentage discount removes part of the current price. After a 20% reduction, 80% remains. A further 10% reduction leaves 90% of that remaining amount. Multiply the remaining proportions: 0.80 × 0.90 = 0.72. You pay 72% of the original, so you save 28%.
The underlying single-discount calculation is covered in OpenStax’s lesson on discounts. Successive discounts repeat that calculation using each new price as the next starting point.
The successive discount formula
Final price = Original price × (1 − first discount ÷ 100) × (1 − second discount ÷ 100).
To find the equivalent total discount, calculate 100 × [1 − (1 − first discount ÷ 100) × (1 − second discount ÷ 100)]. For three discounts, multiply by a third remaining-price factor before subtracting the product from one.
This assumes each percentage applies to the entire remaining eligible price. Fixed-value vouchers, exclusions, maximum savings and minimum-spend conditions need separate treatment.
1. A 20% sale followed by a 10% coupon
Start with a price of 200. The first discount saves 40, leaving 160. The second discount saves 16, leaving 144. Your total saving is 56, and 56 ÷ 200 × 100 = 28%.
Adding the advertised percentages would suggest a price of 140, which is too low. The coupon saves 10% of 160 rather than 10% of the original 200.
2. Two successive 15% discounts
For a product priced at 400, the first 15% discount removes 60 and leaves 340. Applying another 15% removes 51 and leaves 289. The total reduction is 111, equivalent to 27.75% of the original price.
Two identical discounts do not double the saving percentage. The remaining-price calculation is 400 × 0.85 × 0.85 = 289.
3. A 30% discount followed by another 20%
An item priced at 500 becomes 350 after 30% off. The next 20% discount removes 70, giving a final price of 280. The saving is 220, or 44%.
A single 50% reduction on the same starting price would leave 250. Therefore, “30% plus an extra 20%” is a smaller saving than a genuine 50% discount when the percentages apply successively.
4. Three discounts of 10%, 5% and 5%
On an original price of 1,000, the first reduction leaves 900. Applying 5% leaves 855, and another 5% leaves 812.25. The total saving is 187.75, equivalent to 18.775%.
The shortcut is 1,000 × 0.90 × 0.95 × 0.95 = 812.25. Keep sufficient precision during the calculation, then check how the retailer rounds each stage. Intermediate rounding can cause small differences.
5. A percentage discount and a fixed-value voucher
Suppose the original price is 300, the sale reduction is 20%, and a voucher removes 30 from the reduced price. First calculate 300 × 0.80 = 240. Then subtract 30, giving 210. You save 90, or 30% overall.
Here, order matters. Removing the voucher first would leave 270, and taking 20% off that would leave 216. Check the offer terms to learn which sequence actually applies. A fixed-value voucher cannot simply be inserted into the percentage-only formula.
Compare the five examples
| Original price | Discounts | Final price | Total saving |
|---|---|---|---|
| 200 | 20%, then 10% | 144 | 28% |
| 400 | 15%, then 15% | 289 | 27.75% |
| 500 | 30%, then 20% | 280 | 44% |
| 1,000 | 10%, then 5%, then 5% | 812.25 | 18.775% |
| 300 | 20%, then 30 off | 210 | 30% |
Use the percentage tool as a double discount calculator
The tool does not require a dedicated stacked-discount mode. Open the Percentage Calculator, choose “Add or subtract %,” and subtract the first percentage from the original price. Apply the next percentage to that result.
To check the effective saving, use “Increase / decrease %” with the original price as the first value and the final price as the second. A negative percentage change represents the reduction. For example, changing from 200 to 144 gives −28%, meaning a 28% discount.
Frequently asked questions
Can I add two discount percentages together?
Not when the second percentage applies to the already discounted price. Multiply the remaining-price proportions instead.
Does the order of percentage-only discounts matter?
Without intermediate rounding, caps or eligibility changes, it does not. Multiplication gives the same result either way. Fixed-value vouchers and offer conditions can change this.
Do these examples include delivery or tax?
No. They show price reductions only. Compare the checkout total after any delivery charges, applicable taxes and fees.
Check the real saving before choosing an offer
Stacked discounts are easier to compare when you calculate the final price rather than adding the headline percentages. Confirm the eligible amount, follow the stated sequence and check the checkout total. Try the free Percentage Calculator to calculate each reduction and verify the overall saving.