Discount Break-Even Calculator
A free tool from EcomWatchdog, which emails you when competitors change their prices and promotions.
Updated November 2, 2026
A discount comes out of your profit on every sale, so you need more sales to end up with the same profit. Divide your profit per sale before the discount by your profit per sale after it: that's how many times as many sales you need. At a 40% margin, 20% off needs twice the sales.
Planning a Black Friday or Cyber Monday discount? Check what it really costs before you commit to it.
Product cost, plus fees per order if you know them.
Shows what matching it would take.
+100%
more sales needed to make the same profit (2× as many).
Profit per sale: $20 now, $10 at the sale price of $40. Your margin is 40%.
Real example: an electronics brand we track started 20% off sitewide with a code on October 27, 2026, and ended it on November 3. EcomWatchdog reported both the next morning.
| Discount | Profit per sale | Extra sales needed |
|---|---|---|
| 10% off | $15 | 33.3% more |
| 15% off | $12.50 | 60% more |
| 20% off | $10 | 100% more |
| 25% off | $7.50 | 166.7% more |
| 30% off | $5 | 300% more |
| 40% off | $0 | No profit on any sale |
| 50% off | -$5 | Loses money on every sale |
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How it's worked out
- Sale price = your price × (1 − the discount).
- Profit per sale = price − cost, before and after the discount.
- Sales needed = profit per sale before ÷ profit per sale after.
- Extra sales needed = sales needed − 1, as a percentage.
Example
A $50 product that costs you $30 makes $20 a sale. At 20% off it sells for $40 and makes $10 a sale, half as much. So you need twice as many sales, 100% more, just to make the same profit.
Questions
- Why does a small discount need so many more sales?
- The discount comes out of your profit, not out of your price. If you make $20 on a $50 product, 20% off ($10) halves your profit, so you need twice the sales.
- Should I match a competitor's lower price?
- Enter their price in the competitor's price box. The calculator turns it into a discount and shows how many more sales matching it would need. If that's more than you can realistically get, matching may cost you more than it wins.
- What discount is safe for Black Friday?
- There's no single safe number, because it depends on your margin. Use the table to compare common discounts at your margin, and choose one where the extra sales you'd need are realistic.
- Does this include shipping, payment fees and ads?
- Only if you include them in your cost. For a more accurate answer, add what each order costs you beyond the product, such as payment fees, packaging and any shipping you pay.
Competitors starting a sale or cutting a price? EcomWatchdog emails you when they do. Try it free for 14 days.