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Margin Calculator
Profit margin is the share of your sale price you keep as profit — and it is not the same as markup. On a $50 sale with a $10 item cost and $5 of other costs, profit is $35, margin is 70.0%, markup is 233.3% and ROI is 350%. Use this calculator to get all four numbers instantly.
Fees checked October 2026 · Works for any marketplace
YOUR PROFIT
$35.00
Sale $50.00 minus total costs $15.00 = $35.00 profit.
Margin is profit divided by sale price. Markup is profit divided by total costs. ROI here is profit divided by item cost — the return on the money tied up in the item itself.
Margin on a $50 sale — worked example
At the defaults — $50 sale, $10 item cost, $5 other costs:
| Line | Amount |
|---|---|
| Sale price | $50.00 |
| Item cost | $10.00 |
| Other costs (shipping, fees) | $5.00 |
| Total costs | $15.00 |
| Profit | $35.00 |
| Profit margin (35 / 50) | 70.0% |
| Markup (35 / 15) | 233.3% |
| ROI (35 / 10) | 350% |
Margin vs markup — do not mix them up
| Measure | Formula | On a $50 sale |
|---|---|---|
| Profit margin | Profit / sale price | 35 / 50 = 70.0% |
| Markup | Profit / total costs | 35 / 15 = 233.3% |
| ROI | Profit / item cost | 35 / 10 = 350% |
Margin can never exceed 100%, because profit can never exceed the sale price. Markup has no ceiling — a $10 item sold for $50 is a 400% markup before other costs, but only an 80% margin. When a guide says “good margin,” it usually means margin, not markup.
How to calculate margin
Profit = sale price – item cost – other costs (shipping, fees, packaging). Margin = profit / sale price x 100. Markup = profit / total costs x 100. ROI = profit / item cost x 100. Put every real cost into “other costs” — marketplace fees, shipping you paid, packaging, gas — or the margin will flatter you.
5 tips for healthier margins
- Count every cost. The most common margin mistake is forgetting fees and shipping. Run the sale through the matching platform fee calculator first, then enter the real fee total as an other cost here.
- Compare margin across items, not just profit dollars. A $35 profit on a $50 sale (70%) beats a $40 profit on a $200 sale (20%) for your time and cash — margin shows efficiency.
- Watch margin after fees, not before. A thrift find with an 80% gross margin can drop below 50% after marketplace fees and shipping. Judge the after-fee margin.
- Price with a margin floor. Decide your minimum acceptable margin (many resellers use 30-50%) and use our reverse price calculator to find the list price that protects it.
- Track margin by category. Some categories always run thin. If one category averages under 20% after fees, it may not be worth the sourcing time.
Frequently Asked Questions
What is a good profit margin for reselling?
Many resellers target 30-50% after all costs, but it varies by category. Thin, high-volume categories can work at 20%, while rare or refurbished items often need 50% or more. See our guide to good profit margins for reselling (coming with the Phase 2 guides).
What is the difference between margin and markup?
Margin divides profit by the sale price; markup divides profit by costs. On a $50 sale with $15 total costs and $35 profit, margin is 70.0% and markup is 233.3%.
Can profit margin be over 100%?
No. Profit is part of the sale price, so margin tops out below 100%. If you see a margin over 100%, a cost was missed or the formula used markup by mistake.
Does this calculator include marketplace fees?
Only if you include them. Enter your platform fee total in “other costs” — or use a platform calculator first and bring the fee number here.
What is ROI for a reseller?
Return on the money tied up in inventory: profit divided by item cost. A $35 profit on a $10 item is 350% ROI — your money more than tripled on that item.
Related tools & resources
- Reseller profit calculator — profit, margin and ROI by platform
- Break-even calculator — the lowest price you can accept
- Reverse price calculator — price to net a target amount
- All-platform fee comparator — rank 9 marketplaces by your payout
- All marketplace fee calculators — one calculator per platform
- How we calculate fees — sources and update process
Estimate only — not tax or business advice. Fees checked October 2026.