Why use this calculator
Sellers price against the sticker and discover the margin afterwards, which is the wrong order. A fifty dollar sale on a typical marketplace loses roughly seven dollars to fees before postage, and if you also paid for the item and the label, the profit can be a third of what the listing suggested.
The trap is that fees are charged on the order total including the postage the buyer paid, so the shipping you thought was neutral is quietly taxed too. This calculator lays out every fee line, shows the profit, the margin and the return on the cash you actually tied up in stock, and then solves for the break-even price.
That last number is the one you need during an offer negotiation, because it is the point below which you are paying a stranger to take your inventory. It is equally useful in reverse: work out the break-even first, then set a list price that leaves the margin you want rather than the margin that happens to survive.
How to use it
- Pick the platform first, since that sets which fee lines apply, and choose Custom if your marketplace is not listed or if your account is on a different rate.
- Enter the sale or hammer price the buyer pays for the item alone, taken from the listing or the sold record rather than including postage.
- Enter what the item cost you, counting the purchase price plus materials and packaging for this one unit from your receipts or stock sheet.
- Enter the postage you pay, which is the real label price from your carrier account rather than a rounded estimate.
- Enter the postage the buyer pays you, or zero if you advertise free shipping, because that amount is revenue and is usually also part of the fee base.
- Add a promoted or offsite ads percentage only if the platform billing page shows that this particular sale was attributed to an ad.
- The final two fields are used only when the platform is set to Custom.
What each result means
- Platform and payment fees
- Everything the marketplace deducts before you are paid. It is charged on the order value, so it applies even when you sell at a loss.
- Fee breakdown
- Each fee line separately, so you can check it against the settlement report on your seller dashboard rather than trusting a single total.
- Money in from the buyer
- The gross order value, item price plus any postage the buyer paid. This is the figure most fee percentages are applied to.
- Total costs
- Fees, the postage label you buy and the cost of the item itself. It is what the sale consumes before anything is left for you.
- Net profit
- What you actually keep from this order. Track it per listing rather than per month if you want to know which stock is worth rebuying.
- Profit margin on the order
- Profit as a share of what the buyer paid. Useful for comparing listings of very different values on the same scale.
- Return on the cash you put in
- Profit measured against the money you tied up in stock and postage, which is the number that tells you how hard your float is working.
- Fees as a share of the order
- The platform's cut expressed as a percentage. Watching this across platforms is the fastest way to see where your listings belong.
- Break-even sale price
- The lowest price that still covers fees, postage and stock. Treat it as your hard floor when a buyer sends an offer.
The formula
Net profit = sale price + postage charged to the buyer - cost of the item - postage you pay - total fees, all in dollars
Total fees are the sum of the platform lines for the chosen marketplace: a percentage of the order total (sale price plus postage charged), plus any fixed listing or per order charge, plus payment processing expressed as a percentage plus a fixed amount, plus an ads percentage when one applies.
Profit margin = net profit / (sale price + postage charged) x 100
Return on cash = net profit / (cost of the item + postage you pay) x 100
The break-even sale price is solved numerically as the price where net profit equals zero, which handles stepped fee tables that no closed form covers.
How this number is used in practice
The break-even price is the number to have open during offer negotiations. Buyers on every marketplace send low offers as a matter of routine, and the seller who knows their floor to the cent accepts good ones instantly and declines bad ones without agonising. It also changes how you buy.
If a category of stock consistently breaks even at seventy per cent of its resale price, you learn to stop paying more than about a third of resale at the source, because the gap has to cover fees, postage, returns and the items that never sell.
Free postage is the most expensive habit in reselling and the easiest to misprice. Offering free shipping does not remove the cost, it moves it into the item price, and because fees are charged on the order total either way, the fee outcome is broadly the same.
What changes is the psychology of the listing and your exposure when a heavy item sells to a distant buyer. Work out the break-even with the postage you pay set to your worst realistic label, not your average one, or the first interstate sale of a bulky item will wipe out the margin on three normal ones.
Fee schedules move, and they move in your blind spot. Marketplaces routinely adjust percentages, introduce per order charges, change how promoted listings are billed, or shift payment processing into the main fee. The presets here follow the published United States structures and are a sound starting point, but the only authoritative figures are on your own settlement report.
Reconcile one real payout against this calculator each month: if the fee total differs by more than a few cents, switch the platform selector to Custom and enter the rate your account is actually charged. Tax is a separate matter again, because marketplaces report seller income to revenue authorities in most countries, so treat the net profit here as a pre-tax figure and speak to an accountant once selling stops being incidental.
Worked examples
A 50 dollar Etsy sale with 15 dollars of stock, 8 dollars of postage each way
Fees of $7.12, a net profit of $27.88 and a margin of 48.07%
The same Etsy sale attributed to offsite ads at 15 per cent
Fees rise to $15.82 and profit falls to $19.18, a margin of 33.07%
A 120 dollar eBay sale with free postage costing you 12 dollars and 40 dollars of stock
Fees of $16.30, a net profit of $51.70 and a break-even price of $63.42
A 12 dollar Poshmark sale where the flat fee applies and stock cost 6 dollars
A flat $2.95 fee leaves $3.05, a margin of 25.42%
When people use it
- Setting a list price that leaves the margin you want after every fee
- Knowing your hard floor before you accept or counter a buyer's offer
- Comparing what the same item would net on two different marketplaces
- Deciding whether promoted or offsite ads are worth the attributed fee
- Working out the maximum you can pay for stock at an auction or estate sale
Tips
- Reconcile one real payout against this calculator each month. If the totals drift, switch to Custom and enter the rate your account is genuinely charged.
- Set the postage you pay to your worst realistic label rather than your average, so a single heavy interstate sale cannot erase three good ones.
- Fees apply to the postage the buyer pays, so charging postage separately is not free money. It is revenue that gets taxed by the platform like any other.
- Watch the return on cash rather than the margin when stock is cheap. A three dollar item that nets four dollars beats a fifty dollar item that nets six.
- Price above break-even by enough to absorb one return in ten. Returned items usually come back with the outbound postage already spent.
- Promoted ads are billed on the whole order, not on the advertising you think you bought, so check the attribution rules before leaving them switched on.
What it assumes, and where it stops being accurate
- Fee presets follow the published United States structures for each marketplace and are quoted in United States dollars. Rates differ by country, by currency and sometimes by seller tier, so verify against your own settlement report.
- Assumes one item in one order. Multi-item orders share a single per order fee and often a single postage label, so per item profit is better than this model suggests.
- Poshmark's fee is applied to the item price only, because the shipping label is bought by the buyer. Enter zero in both postage fields for a normal Poshmark sale.
- Excludes subscription or shop fees, currency conversion, international payment surcharges, return postage, refunds and unsold stock write-offs.
- Not accurate for sales tax, VAT or GST. Marketplaces collect and remit consumption tax in most jurisdictions, so it should not appear in your revenue or your fee base here.
- Income tax, self employment tax and business registration obligations are outside this calculation. Net profit here is a pre-tax number.
Terms used on this page
- Cost of goods sold
- What one unit cost you to acquire and prepare, including materials and packaging but not overheads.
- Final value fee
- A percentage the marketplace takes from the total order value once an item sells, charged on postage as well as price.
- Payment processing fee
- A separate charge for handling the card or wallet transaction, usually a percentage plus a small fixed amount.
- Offsite or promoted ads fee
- A percentage charged when the marketplace attributes the sale to advertising it ran on your behalf.
- Break-even price
- The sale price at which profit is exactly zero once fees, postage and the cost of the item are covered.
Questions people ask
- Why are the fees charged on postage as well as the item?
- Most marketplaces apply their percentage to the full order value, including any postage the buyer paid, because that is the amount processed through their payment system. It means shipping is never truly neutral, and it is the single most common reason a seller's calculated margin is higher than their real payout.
- Are these the exact fees my account is charged?
- They are the published structures rather than your account's live rates. Seller tiers, promotional periods, country of registration and category can all change what you actually pay, so reconcile against one real settlement report and use the Custom option if your numbers differ.
- What does the break-even sale price include?
- It includes the cost of the item, the postage you pay and every fee that would apply at that price, including any ads percentage. It is solved numerically rather than with a formula, so it stays correct on platforms with stepped fees such as Poshmark's flat charge under fifteen dollars.
- Should I include sales tax, VAT or GST?
- No. Marketplaces collect and remit consumption tax to the authorities in most jurisdictions, so it never belongs to you and should not appear in your revenue or your fee base. If you are registered for GST or VAT on your own account, handle that separately with your accountant.
- How do I use this to decide what to pay for stock?
- Work backwards. Enter the realistic resale price, your usual postage and a cost of zero, then read the profit as your maximum spend at that margin. Most experienced resellers land on paying between a quarter and a third of expected resale once fees, returns and dead stock are absorbed.
- Does a free shipping promotion change the fee?
- Not usually. If you raise the item price to absorb postage, the order total stays similar and so does the percentage fee. What changes is your exposure to heavy or distant parcels, because you have fixed your revenue while the label cost still varies with the buyer's address.
Use this with
Marketplace Seller Fee and Profit Calculator answers one part of the question. These pick up where it stops: Profit Margin Calculator, Markup Calculator, Pricing Strategy Calculator and Break-Even Calculator.
Where these figures come from
Figures and rules on this page follow United States federal rules.
- Etsy Fees and Payments Policy. Listing, transaction, payment processing and offsite ads fee structure
- Internal Revenue Service, Small Business and Self-Employed Tax Center. United States reporting obligations for marketplace and reseller income
- Australian Taxation Office, businesses and organisations. When online selling becomes a business for Australian tax purposes
Marketplace Seller Fee and Profit Calculator produces an estimate for general information. It is not financial, tax, medical, legal or engineering advice. read the full disclaimer. Spotted a wrong number? Report it and it gets fixed. The form picks up this calculator and the inputs you used.