How do I calculate profit on a resold item?

Take the sale price and subtract every cost: item cost, platform selling fee, payment processing, postage, packaging, and any refund. What's left is your net profit. Divide by the sale price for margin, or by your costs for ROI.

Should I include unsold stock in my profit?

Yes. The money you spent on items that didn't sell is a genuine cost of the business. Ignoring it makes your margin look better than reality and leads to overpaying when sourcing.

What's a good profit margin for reselling?

It varies by niche, but many UK clothing resellers aim for over 50% margin on lower-value items and accept lower margins on higher-value pieces where the absolute profit is still strong.

Do I need software, or is a spreadsheet enough?

A spreadsheet can work if you keep it up. Most people don't, especially once volume grows. Software like ResellIQ removes the manual entry so the tracking actually survives a busy week.

Guide

How to track reselling profit (and the fees that eat it)

Plenty of resellers are busy, moving stock every week, and have no idea whether they're actually making money. The sale price feels like profit, but it isn't — fees, postage and the items that never sold quietly take a big bite. Here's how to track the real number.

28 June 2026 · 8 min read

Key takeaways

—Profit is sale price minus every cost: item, platform fees, payment fees, postage, packaging.
—Unsold stock is a real cost — ignoring it makes your profit look better than it is.
—Track margin (profit ÷ sale) and ROI (profit ÷ cost) together, not just absolute profit.
—The system only works if it's low-effort enough that you actually keep it up.

Why sale price isn't profit

Say you sell a hoodie for £30. It feels like a £30 win. But you paid £6 for it, eBay took roughly £3 in fees, postage was £3.30, and the mailer and tape cost £0.40. Your actual profit is about £17.30 — a bit over half the sale price. Do the same maths across a month and the gap between 'total sales' and 'actual profit' is usually a shock the first time someone sees it.

This matters because sourcing decisions depend on the real number. If you think your margin is 80% when it's really 55%, you'll overpay when buying stock and slowly squeeze yourself. Tracking profit properly isn't bookkeeping for its own sake — it's what tells you how much you can afford to pay for the next item.

Every cost you need to count

A complete profit calculation includes all of these:

Item cost — what you paid to acquire it, including any sourcing travel where you can attribute it.
Platform selling fee — eBay's final value fee, or a marketplace commission; varies by platform.
Payment processing — where it's charged separately from the selling fee.
Postage — the label cost, especially when you offer free or subsidised shipping.
Packaging — mailers, boxes, tape, tissue; small per item, real over a month.
Refunds and returns — money that comes back out after a sale you'd already counted.

The cost everyone forgets: unsold stock

Here's the one that makes profit reports lie. If you buy a 20-item bundle for £40 and only 14 of them ever sell, the cost of all 20 still came out of your pocket. If you only count the cost of the 14 that sold, your margin looks great and your bank balance disagrees.

Proper profit tracking keeps unsold stock visible as a real cost. It doesn't mean every item must sell — it means your numbers should reflect that some won't. Resellers who track this source more carefully, because they can see the drag that dead stock puts on the whole operation.

Margin vs ROI — track both

Profit margin is profit as a percentage of the sale price; it tells you how much of each sale you keep. ROI is profit as a percentage of what you spent; it tells you how hard your money is working. A £5 item flipped for £25 has a huge ROI but a small absolute profit. A £60 item flipped for £100 has a lower ROI but pays your bills faster.

Watching only one of them skews your decisions. Track both per item, and look at absolute profit too, so you're not chasing impressive percentages on items too cheap to matter.

Build a system you'll actually keep up

The best profit-tracking system is the one you don't abandon after two weeks. A spreadsheet works if you're disciplined, but most people stop updating it the moment they get busy — which is exactly when the data matters most. The fix is to remove the friction: log the cost when you buy, and let sales and fees flow in automatically.

ResellIQ does this by attaching a cost to every item, subtracting platform fees, postage and packaging automatically, and even turning your marketplace sold-emails into tracked sales so you don't type them in. Margin and ROI are calculated for you, per item and per platform — which means the number is always there when you're standing in a charity shop deciding whether to buy.