How much more do you need to sell after a discount?
Divide the contribution per order without the discount by the contribution with it – that factor is how many orders you need to earn the same. For a €49.90 product with typical costs, 20 % off drops the contribution from €12.68 to €5.16: you need 146% more orders just to break even with a normal week.
Enter your own price, costs and discount – the calculator shows the increase you need and your maximum discount.
Open the discount calculatorThe formula
A discount reduces the price, but not the costs that come with every order: product, shipping, packaging, advertising and returns stay the same. Only percentage fees shrink a little with the lower price. That is why the contribution per order falls much faster than the price.
| Sales factor | contribution without discount ÷ contribution with discount |
|---|---|
| Sales increase needed | sales factor − 1 |
| Maximum discount | 1 − break-even price ÷ regular price |
Table: sales increase needed per discount
Same product (€49.90 incl. VAT, purchase price €15.00, shipping €4.90, €5.00 ads per order, 8 % returns). Contribution without discount: €12.68 per order.
| Discount | Contribution per order | More orders needed |
|---|---|---|
| 5% | €10.80 | +17% |
| 10% | €8.92 | +42% |
| 15% | €7.04 | +80% |
| 20% | €5.16 | +146% |
| 25% | €3.29 | +286% |
| 30% | €1.41 | +802% |
Black Friday checklist
Big sale weeks combine deep discounts with expensive advertising. Before you set the discount:
- Calculate the maximum discount for every product – anything above it loses money on each order.
- Use the ad cost per order you expect in the sale week, not your average.
- Plan with contribution (orders × contribution per order), not revenue.
- Prefer discounts on products with high margins, bundles or a free gift with a low cost instead of a flat percentage.
- Decide how many extra orders are realistic – the calculated increase is the minimum, not a forecast.
Worked examples: 20 % off a €49.90 product
Regular price €49.90 incl. 19 % VAT, purchase price €15.00, shipping €4.90, payment fee 2 % + €0.30, €5.00 ads per order, 8 % returns at €5.00 each, 100 orders a month.
- Price with discount
- €39.92
- Contribution per order without discount
- €12.68
- Contribution per order with discount
- €5.16
- Sales factor
- × 2.46
- Orders per month needed (instead of 100)
- 246
- Maximum discount before every order loses money
- 34%
Without more orders the month brings €516.41 instead of €1,268.02. The discount only pays off if it really brings 246 orders.