Plan sales without losing money
Discount calculator
Work out the sale price and savings for any percentage off, and see what the discount does to your profit and how many more sales you'd need.
Rates checked October 6, 2026
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The discount
Your normal price and the discount you're planning.
Your normal selling price.
Percentage off the full price.
Everything one sale costs you: product, shipping, packaging and fees.
Used to show how many discounted sales you'd need.
Sale price
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Sale price split
Full breakdown
Every amount for one sale, with its share of the total.
| Item | Amount | Share |
|---|
How to calculate a discount
Sale price = full price × (1 − discount)
Saving = full price × discount
20% off $40 is $40 × 0.8 = $32, a saving of $8. That part is easy. The part sellers forget is what the discount does to profit, because the whole saving comes out of your margin.
What a discount does to your profit
Say an item sells for $40 and costs you $24 in product, shipping and fees, so you make $16. At 20% off you still pay $24, but now you sell for $32 and make $8. Half your profit is gone, so you need to sell twice as many to end up with the same money.
| Discount on a $40 item costing $24 | Profit per item | Extra sales needed |
|---|---|---|
| No discount | $16 | — |
| 10% off | $12 | +33% |
| 20% off | $8 | +100% |
| 25% off | $6 | +167% |
| 30% off | $4 | +300% |
Sales needed = profit at full price ÷ profit at sale price
When discounts make sense
- Clearing old stock that would otherwise sit unsold.
- Winning new customers who are likely to come back and buy at full price.
- Raising order value, such as 15% off orders over $60, so the discount pays for itself.
Before a sale, check your margin with the profit calculator. Products with thin margins can turn into a loss with even a small discount. Our guide on how discounts affect profit goes deeper.
Frequently asked questions
How do I calculate 20% off?
Multiply the price by 0.8. 20% off $40 is $32, a saving of $8.
How do I calculate the original price from a sale price?
Divide the sale price by 1 minus the discount. A $32 price after 20% off came from $32 ÷ 0.8 = $40.
How many more sales do I need after a discount?
Divide your profit at full price by your profit at the sale price. If profit drops from $16 to $8, you need twice the sales.
Is a percentage discount or a fixed discount better?
Neither is always better. Fixed amounts like $5 off feel bigger on cheap items; percentages feel bigger on expensive ones. Check the profit either way.