Here I redo the math the statement doesn’t show: how much you keep from each sale on Mercado Livre and Shopee, where fees eat into your margin without warning, and how to set prices without guesswork. Straight to the point, with real 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.
From R$ 79, the shipping cost jumps to a new tier that depends on the package weight. For a 10 kg item, it only pays off again above R$ 125. See the step table by weight.
Full charges storage per day and per idle unit. Before sending stock, calculate the SKU’s coverage days. Over 90 days, Mercado Livre’s warehouse becomes your biggest hidden cost.
Winning the catalog listing isn’t about being the cheapest. And if you’re going to lower your price, drop it past the R$ 79 step: going from R$ 80 to R$ 78.99 actually increases your margin instead of reducing it.
In cost-sharing campaigns, Mercado Livre covers part of the discount, and the promotional sale can pay more than the full-price sale. The problem is the refund doesn’t always show up in your statement.
On Shopee, raising the price from R$ 79.99 to R$ 80.00 takes R$ 6.69 out of your pocket. There are three steps like this in the commission table, and I show where each dead zone starts and ends.
Shopee pays you the net amount, with fees already deducted before you see it. This changes how you check your margin and hides mistakes that would be obvious on Mercado Livre.
ABC curve by revenue shows who sells. By margin, it shows who pays the bills. The names rarely match on both lists, and the difference is where the decisions are.
Losing green reputation on Mercado Livre makes shipping more expensive for all listings above R$ 79 at once. See what counts in the calculation, what doesn’t, and which metric to watch every week.
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.