How to calculate profit on a resale
A sale price is not the same as profit. The difference between the money your buyer pays and everything you spend to make the sale is your net profit. This includes what you paid for the item, shipping, packing supplies, and fees taken by a marketplace or payment provider.
Net profit = item price + shipping paid by buyer − item cost − shipping cost − packaging − other costs − marketplace fees. The tool also calculates net margin (profit divided by sales received) and return on cost, or ROI (profit divided by the costs you invested). These are different measures: margin tells you how much of the revenue remains; ROI tells you how productive your investment was.
Worked example
You bought an item for $40 and sold it for $100. The buyer paid $5 for shipping, but shipping cost you $8 and packaging cost $2. A 10% marketplace fee plus $0.30 fixed fee is charged on the $105 received. Your estimated fees are $10.80 and profit is $44.20.
Common mistakes
Do not forget the cost of mailers, labels, promoted listings, and refunds. Some marketplaces also calculate percentage fees on buyer sales tax, even though that tax is not your revenue; enter buyer tax if that applies. For accurate eBay or Etsy examples, use the dedicated calculators.
Frequently asked questions
What is the difference between profit margin and ROI?
Profit margin divides net profit by sales revenue. Return on cost (ROI) divides net profit by your invested costs. For example, $20 profit on $100 in revenue is a 20% margin, while $20 profit on $80 in costs is a 25% return on cost.
Does shipping affect resale profit?
Yes. Add the shipping amount collected from your buyer to revenue, then subtract what you actually pay for shipping and packaging. The calculator handles these as separate fields so you can see the real impact.
Can I use this for any marketplace?
Yes. Enter the correct percentage and fixed fees for the platform, country, category and plan you use. It is a general calculator, not an official marketplace statement.