Discount Impact Calculator
See how many more sales a discount needs just to earn the same profit.
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Why discounts cost more than they look
A discount comes straight out of your profit, not out of your price. If a product makes $20 profit on a $50 price, a 20% discount removes $10 — half of the profit on every unit. To end up with the same money, you would need to sell twice as many units. Small sellers often run a sale, see a jump in orders, and still earn less than in a normal week.
This calculator shows the sales increase a discount has to produce just to break even with your normal profit. If you do not think the sale will bring that many extra customers, it is costing you money.
The formula
Sale price = price × (1 − discount %)
Profit per unit = price − cost
Sales multiplier = normal profit per unit ÷ sale profit per unit
Extra sales needed = (multiplier − 1) × 100
Worked example
A product sells for $50 and costs $30 to make and deliver, so each sale earns $20. A 20% discount drops the price to $40 and the profit to $10. $20 ÷ $10 = 2, so you need 100% more sales — double the normal number — to earn the same profit.
Quick reference
Extra sales needed to keep the same profit, by normal margin and discount:
| Margin | 10% off | 20% off | 30% off |
|---|---|---|---|
| 30% | 50% | 200% | Not possible |
| 40% | 33% | 100% | 300% |
| 50% | 25% | 67% | 150% |
| 60% | 20% | 50% | 100% |
Frequently asked questions
When is a discount still worth it?
When it brings in customers who will buy again, clears stock you would otherwise not sell, or helps a new product get its first reviews. Those benefits are real, but they should be weighed against the profit you give up.
What if the discount is bigger than my margin?
Then every discounted sale loses money and no amount of extra volume makes up for it. The calculator will show this.
Should cost include platform fees?
Yes. Include everything you pay per sale. Note that percentage-based fees fall slightly when the price drops, so the real result may be a little better than this estimate.