Profit margin calculator
Reseller profit margin calculator
A platform-agnostic calculator for any flip. Enter what you paid, what it sold for, and the fees and costs involved, and get your net profit, profit margin and ROI in one place — before you commit to a buy or after a sale.
- Total marketplace fees
- £2.50
- You receive (payout)
- £22.50
- Net profit
- £22.50
Fully editable — set the selling fee, fixed fee and payment processing to match whatever platform you're modelling (eBay, Depop, Whatnot, Etsy, Grailed, your own store). Defaults to a 10% selling fee as a starting point. Last reviewed June 2026.
Margin vs ROI — and why both matter
Profit margin is your profit as a percentage of the sale price: it tells you how much of each pound a customer spends you actually keep. ROI (return on investment) is your profit as a percentage of what you spent to get the item: it tells you how hard your money is working. A flip can have a great margin but poor ROI, or vice versa, and resellers who only watch one of them make worse sourcing decisions.
Example: you buy a jacket for £8 and sell it for £40 with £4.30 in fees and £3 postage. Profit is £24.70. That's a 62% margin (£24.70 of the £40 sale) and a 309% ROI (£24.70 on the £8 you risked). The big number that gets people excited is the ROI; the number that pays your bills is the absolute profit.
Use it before you buy, not just after you sell
The most valuable time to use this calculator is at the point of sourcing. If you can estimate the likely sold price and the fees, you can work backwards to a maximum buy price that still leaves the margin you need. That discipline is the difference between resellers who grow and resellers who are busy but broke.
Doing this by hand for every item is the friction that stops most people. ResellIQ builds the maths into your inventory: log the cost when you buy, mark it sold, and profit, margin and ROI are calculated for you — per item, per platform, and across your whole business.
Frequently asked
- How do I calculate reselling profit margin?
- Profit margin = (sale price − all costs and fees) ÷ sale price × 100. Enter your sale price, item cost, fees and postage into the calculator and it does it instantly, alongside ROI.
- What's a good profit margin for reselling?
- It varies by niche and item value, but many resellers aim for a margin above 50% on lower-value clothing and are happy with lower margins on higher-value items where the absolute profit is still strong. Watch both margin and absolute profit together.
- Does this work for eBay, Depop, Whatnot and others?
- Yes. It's platform-agnostic — set the selling fee, fixed fee and payment-processing fields to match any marketplace, or use our dedicated eBay, Vinted, Depop and Whatnot calculators for pre-filled defaults.
- What costs should I include?
- Everything that touches the item: purchase price, platform and payment fees, postage labels, packaging, and a share of sourcing costs where relevant. The more complete your costs, the more honest the margin.