What you keep from each sale: margin, markup, cost of goods sold (COGS), selling price, and the numbers your statement doesn't show.
Markup is the multiplier that takes you from cost to price: a cost of R$ 40 with a markup of 2 gives you a price of R$ 80. The math is simple, but on Mercado Livre and Shopee, that markup leaves you with a 9% to 14% margin—not the 50% it seems to. See the right formula, the divisor markup, and examples.
Selling price = (cost + fixed costs per unit) ÷ (1 − commission − tax − ADS − margin). With a cost of R$ 25 and a 15% margin, the price comes to R$ 50,37 on Mercado Livre and R$ 51,02 on Shopee. See the formula step by step and the pricing-tier mistake almost everyone makes.
Profit margin = (price − all sale costs) ÷ price × 100. A product priced at R$ 100 that leaves R$ 26,45 after commission, shipping, tax, and cost has a 26,5% margin. See the formula, how to calculate it in Excel, and what margin Mercado Livre and Shopee sellers need to cover Ads and expenses.
Gross margin subtracts only the product cost; contribution margin also subtracts commission, shipping, tax, and Ads; net margin also subtracts fixed expenses. For a store that earns R$ 100 mil per month on Mercado Livre, a 54% gross margin becomes an 18,4% contribution margin and a 9,4% net margin. See how to calculate each one.
Profit on a sale = price − all sale costs. Profit percentage can be based on the sale (26,45% on a R$ 100 product that leaves R$ 26,45) or on the cost (66,1% on the same product). See the formulas, how much a 10% discount cuts into profit, and how many sales you need to make R$ 10 mil in profit this month.
To price a product for resale, start with its actual acquisition cost (not the supplier's price), add the channel fees, and set a floor, target, and ceiling. For a product bought for R$ 19,90, the floor on Mercado Livre is R$ 36,77, and the price for a 15% margin is R$ 45. See the step-by-step breakdown with the numbers.
Cost of goods sold (COGS) is the cost of the products you sold: beginning inventory + purchases − ending inventory. If a store started the month with R$ 30 mil in stock, bought R$ 40 mil, and ended with R$ 36 mil, its COGS was R$ 34 mil. See the formula, weighted average cost, what does and doesn’t count toward a marketplace seller’s COGS, and what share of revenue it should represent.
Revenue is what the buyer pays; profit is what's left after the product, commission, shipping, tax, listing, and fixed expenses. One store brought in 31% more revenue during a promotion but made 16% less profit that same month. See the numbers, the four most common reasons, and what to track instead of revenue.
A listing that loses money rarely looks unprofitable: it sells, brings in revenue, and gets lost in the store average. The six most common traps are products under R$ 30, prices just above a pricing threshold, heavy packages, Premium listings with paid ads, promotions combined with coupons, and outdated costs. Learn how to spot each one by running the numbers for six real listings.
A marketplace pricing spreadsheet needs columns for cost, weight, category commission, shipping cost by price range, tax, Ads, and margin—and a formula that divides instead of multiplies. See the column layout, formulas for Excel and Google Sheets, common mistakes, and Milewa’s free spreadsheet.
Before buying stock to sell on Mercado Livre or Shopee, answer six questions: Is there demand? What price does it sell for? How much is left at that price? How quickly does it sell? How much capital will it tie up? What's the risk? A product with a 25% margin that sells through in 30 days earns more than one with a 35% margin that takes 120 days. See the test and how to calculate your return on stock.
Since March 2026, Shein has charged an 18% commission on the final price for most categories, 20% for women’s clothing, and 0% for the first 30 days. Commission applies only to delivered orders, and payouts are made weekly, 7 days after delivery. See the official policy, what hasn’t been made public, and a side-by-side comparison with Mercado Livre and Shopee.
Magalu’s marketplace has no monthly fee. The standard commission cited by the company is 18%, with a 9.9% promotion for new sellers, plus a fixed fee per item priced above R$ 10. Magalu Entregas shipping costs are shared with the seller, with a subsidy only for orders above R$ 79. You can sell only with a CNPJ that has been active for more than 3 months. See the rules and the numbers.
The full breakdown of a R$ 100 sale on Mercado Livre: commission, shipping cost, tax, packaging, and what actually goes into your pocket. With numbers from the official shipping cost table checked in September 2026.
Using the price from the first purchase or the last one to calculate margin distorts the result. See the difference between first purchase cost, weighted average cost, and replacement cost, and when to use each one.
The marketplace refunds commission and shipping on returns, but the sale disappears and the return has a cost. See the real calculation and why partial refunds are usually the cheapest way out.
Commission and tax are percentages of the price, so adding them to the cost is wrong. The right formula divides, not adds. And in marketplaces, there’s usually more than one price that gives you the same margin.
Under Simples Nacional, the effective tax rate follows your revenue from the last 12 months. Growing from R$ 500,000 to R$ 2 million cuts more than 3 margin points from all products, with no change in price or cost.
Milewa pulls your orders from Mercado Livre and Shopee, applies commission, shipping, tax, ADS, and your cost, and shows the margin for each order and each SKU. You can start with the calculator and then connect your store.
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