HTM Profit Margin Calculator
Calculate your true profit, ROI, and profit margin before you invest in inventory.
Marketplace fees below are estimates and can vary by category, seller plan, location, taxes, promotions, and marketplace policy — always confirm your actual rate with the marketplace before relying on these numbers.
Deal details
Fill in what you know — results update as you type.
Product
Marketplace fees
Sources last checked July 27, 202613.6% is eBay's non-Store final value fee for MOST categories, not a universal rate — actual eBay fees vary by category, Store subscription tier, seller performance level, and price tier (some categories differ significantly: sneakers $100+ run 8% with no per-order fee, media ~15.3%, guitars & basses 6.7%; a Basic Store subscription drops the rate to ~9.35% + a monthly fee). The per-order fee is $0.30 for an order total of $10.00 or less and $0.40 for orders over $10.00 — resolved automatically from your price, quantity, and shipping unless you type your own value. eBay's fee base can also include buyer-paid sales tax, which this calculator does not model, so your actual eBay fee may run slightly higher than this estimate.
Shipping, tax & other costs
Every field in this section is a TOTAL for this order — none are multiplied by quantity.
Risk buffer (optional)
An optional cushion for returns, damage, or other unexpected costs — factored into every result below. Defaults to $0.
Labor time (optional)
Target controlsOptional
Enter a selling price to see your results
Add at least a purchase price and expected selling price — results update live as you type.
How the calculator works
Every result on this page comes from the formulas below, applied to exactly what you entered — nothing is estimated from outside data. Marketplace fee percentages are editable starting points — some are checked directly against that marketplace's own official documentation, others are general estimates where no official published rate exists (see the source badge next to each marketplace's fee note) — so your actual payout may still differ from what a marketplace ultimately deposits. eBay's own fee base can also include buyer-paid sales tax, which this calculator doesn't model, so an eBay estimate may run slightly higher in reality than what's shown here.
- Gross product revenue
- selling price (per unit) × quantity
- Total revenue
- gross product revenue + shipping charged to customer (total)
- Fixed fee, resolved to a total
- per_order mode: fixed fee as entered · per_unit mode: fixed fee × quantity
- Choose per-order or per-unit next to the fixed fee field — it changes how much this fee grows with quantity. For eBay specifically, the per-order amount is resolved automatically from your order total ($0.30 at $10.00 or under, $0.40 above — eBay's official per-order fee tiers) unless you type your own value.
- Marketplace fees
- max(fee % × total revenue, minimum fee) + total fixed fee
- The percentage fee is applied to total revenue, which includes shipping charged to the buyer — most marketplaces, eBay included, charge their cut on shipping too. A minimum fee (Facebook Marketplace's $0.80 on shipped orders, for example) REPLACES the percentage fee when the percentage alone would be lower — it's a floor, not an add-on, which is why it's kept separate from the fixed fee (always additive) in the math above.
- Risk buffer
- fixed dollar amount, OR buffer % × total revenue
- Percentage mode uses the same base as the marketplace fee (total revenue) — not the same base as percentage-mode advertising, which uses product revenue only.
- Net profit
- total revenue − (inventory cost + marketplace fees + shipping cost + sales tax + packaging + advertising + risk buffer + other expenses)
- Profit margin
- net profit ÷ total revenue × 100
- Return on investment (ROI)
- net profit ÷ total investment × 100
- Total investment is the money you spend up front to do the deal — inventory, sales tax, packaging, seller-paid shipping, advertising, and the risk buffer. Marketplace fees aren't included because they're deducted from your proceeds after the sale, not paid out of pocket beforehand. When total investment is exactly $0, ROI is undefined (shown as "—"), not 0% or ∞%.
- Break-even selling price
- the minimum price that makes net profit ≈ $0
- Solved algebraically so percentage fees, percentage-based advertising, and a percentage-based risk buffer are all accounted for correctly, not just added on top of a flat guess.
- Hourly profit
- net profit ÷ hours worked
- Only shown when you enter labor hours.
What is profit margin?
Profit margin is the percentage of your total revenue that you actually keep as profit after every expense — inventory cost, marketplace fees, shipping, and everything else. A $10 profit on a $100 sale is a 10% margin; the same $10 profit on a $20 sale is a 50% margin. Margin tells you how efficient a deal is, independent of how big the sale was.
Profit margin vs. ROI
Profit margin measures profit against revenue; return on investment (ROI) measures profit against what you actually spent to acquire and sell the item. A low-cost item resold at a modest price can post a thin margin but a huge ROI, because you risked very little cash to earn it. Resellers with limited capital often care more about ROI — how hard their money is working — while margin is more useful for comparing pricing efficiency across very different deal sizes.
How reseller profit is calculated
Net profit is total revenue (your selling price, plus any shipping you charge the buyer) minus every expense it took to make the sale: what you paid for the item, the marketplace's cut, your own shipping and packaging costs, sales tax you paid on the inventory, advertising, and anything else. Whatever is left after all of that is what you actually keep. See the How the calculator works section above the results for the exact formulas this tool uses.
Why marketplace fees matter
Marketplace fees are often the single largest expense in a reselling deal, and they're easy to underestimate — a percentage fee applied to your full selling price (and often the shipping you charge, too) can quietly erase a margin that looked healthy at a glance. Because fee structures change often and vary by category, seller plan, payment method, and promotions, this calculator treats every marketplace fee as an editable estimate rather than a guaranteed number — always double-check your actual rate.
What is a good profit margin for reselling?
There's no single number that works for every category, but many resellers use rough benchmarks: under 10-15% margin is thin and leaves little room for returns or price drops, 15-30% is generally healthy, and 30%+ with a strong ROI is a standout deal. Fast-moving, low-risk inventory can justify a thinner margin than an item that might sit unsold for months — this calculator's targets are adjustable so you can set the bar that fits your own business.
How to calculate a break-even selling price
Break-even price is the lowest price you could sell at and still land at roughly $0 net profit, given your purchase price, fees, and other costs. Simply adding up your expenses and calling that the break-even point overstates it whenever fees are a percentage of the sale — as your price goes up, so does the fee, so the math has to be solved rather than just summed. This calculator does that solve automatically and shows the result in the Break-even price stat above.