Reveal true margin after discounts, fees, and tax. Compare net profit, break-even price, and recovery. Plan every promotion with clearer confidence and healthier margins.
| Scenario | List Price | Discount | Coupon | Revenue Before Tax | Total Cost | Net Profit | Margin |
|---|---|---|---|---|---|---|---|
| Sample campaign | $120.00 | 18% | $5.00 | $97.40 | $80.77 | $16.63 | 17.08% |
| Seasonal push | $120.00 | 25% | $8.00 | $86.00 | $78.07 | $7.93 | 9.22% |
| Heavy markdown | $120.00 | 35% | $10.00 | $72.00 | $74.43 | -$2.43 | -3.38% |
Discounted Item Price = (Original Selling Price × (1 − Discount% ÷ 100)) − Coupon Value
Revenue Before Tax per Unit = Discounted Item Price + Shipping Charged to Customer
Total Fees = Marketplace Fee + Payment Fee + Fixed Fee + Returns Reserve, where each percentage fee is applied to the relevant sales base.
Total Cost per Unit = Product Cost + Seller Shipping Cost + Packaging Cost + Advertising Cost + Total Fees
Net Profit per Unit = Revenue Before Tax − Total Cost per Unit. Margin % = (Net Profit per Unit ÷ Revenue Before Tax) × 100
The calculator first solves the break-even selling price, then converts that price into the maximum safe discount rate from the original selling price.
Step 1: Enter the original selling price and the product cost. These two values define your pre-discount reference economics.
Step 2: Add the promotion details, including discount percentage and any extra coupon value. The tool subtracts both in the correct order.
Step 3: Fill in variable selling costs such as marketplace fee, payment processing, shipping cost, packaging cost, and ad spend.
Step 4: Add tax and return reserve assumptions. Tax is displayed separately, while return reserve is treated like a cost buffer.
Step 5: Press the calculate button. Review the results, export the CSV, download the PDF, and study the Plotly graph for discount sensitivity.
It shows the profit rate remaining after the selling price is reduced and key selling costs are deducted. This metric helps you judge whether a promotion still creates healthy contribution.
Sales tax is often collected from the buyer and remitted later. Because it usually does not belong to the seller, the calculator reports it separately instead of counting it as operating profit.
Yes, when the buyer pays shipping, that amount offsets your fulfillment expense. The calculator adds customer shipping revenue and subtracts seller shipping cost to show the net effect.
A returns reserve acts like a risk buffer. It helps you estimate realistic margin when some orders may be refunded, damaged, or reprocessed after delivery.
It is the largest discount rate you can offer before net profit falls to zero. Going beyond that point means the promotion starts creating a loss.
Yes. It first applies the percentage discount to the original selling price and then subtracts the fixed coupon amount, which mirrors common ecommerce promotion structures.
Yes. The marketplace fee, payment fee, fixed fee, and shipping fields make it suitable for platform-based selling, including stores with multiple transactional deductions.
Discounts reduce selling price first, while many costs remain fixed or only shrink slightly. When fees, shipping, and advertising stay high, even small price cuts can erase profit fast.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.