How to calculate your real profit margin in ecommerce (formula + examples)
Learn how to calculate your real profit margin in ecommerce and on MercadoLibre: the formula, the costs that slip through and a step-by-step example.
"I buy it for $5, sell it for $30, and pocket $25." If that's how you do the math, you're going to lose money. Your real ecommerce margin takes a lot more than subtracting the product cost from the price.
In this guide, you'll learn how to calculate your real margin, which costs are slipping through the cracks, and how to run the numbers before you buy.
The real margin formula
Margin (%) = ((Sale price − Total cost) / Sale price) × 100
Sounds simple. The catch is what you count as "total cost."
Total cost = more than you think
| Component | Description |
|---|---|
| Product cost | What you pay your supplier |
| International freight | Shipping from the supplier, if you import |
| Import duties | Tariffs and taxes, depending on your country and the product |
| Shipping to the customer | What you pay to get the product to the buyer |
| Marketplace selling fee | On MercadoLibre, it depends on the country, the category and the listing type |
| Packaging | Box, filler, labels, tape |
| Payment processing | On your own store, what the payment gateway charges; on a marketplace, check what the selling fee already covers |
| Returns | What you lose on products that come back |
| Marketing | Advertising, discounts and promotions |
MercadoLibre's selling fees and shipping costs vary by country and get updated. Always use the current rates MercadoLibre publishes in its Help Center.
Step-by-step example (with hypothetical numbers)
The numbers in this example are made up to show how the math works. Swap in your own.
Say you find a product for $5.
| Item | Cost |
|---|---|
| Product | $5.00 |
| International freight | $1.50 |
| Import duties | $3.25 |
| Subtotal: landed cost in your country | $9.75 |
| Packaging | $0.50 |
| Shipping to the customer | $2.00 |
| Total cost (before selling fee) | $12.25 |
If you sell it for $30, and assuming a 13% selling fee:
| Item | Amount |
|---|---|
| Sale price | $30.00 |
| Selling fee (assumed: 13%) | −$3.90 |
| Net revenue | $26.10 |
| Total cost | −$12.25 |
| Profit per unit | $13.85 |
| Real margin | 46.2% |
At first glance it looked like 83% ($5 vs. $30). In reality it's 46%, and that's before marketing and returns.
What's a good margin?
There's no universal number: it depends on the category, the volume you sell and how much you spend on ads. A rough way to read it:
| Margin | How to read it |
|---|---|
| Low | Any surprise (a return, a cost increase) puts you in the red |
| Medium | Works if you have volume and tight cost control |
| High | Leaves room for ads, discounts and mistakes |
The key: set your own minimum before you buy, and don't list anything that falls short of it. If you have to drop the price below that minimum to sell, the product doesn't work for you as is.
Hidden costs nobody tells you about
1. Exchange rates
If you buy in dollars and sell in a local currency, the exchange rate can work for you or against you. With high inflation, keep in mind that restocking will cost more than your first order.
2. Time
Your time is worth something. If you spend hours packing orders, that's a cost. Divide your monthly profit by the hours you put in and you'll know what you're actually earning per hour.
3. Inventory that doesn't sell
What you bought and haven't sold is also a cost. For example: if you buy 100 units and sell 70, the other 30 eat into your profit. Start with small orders and scale based on data.
4. Customer acquisition cost (CAC)
For example: if you spend $500 on ads and get 20 customers, your CAC is $25 per customer. That money comes out of your margin.
How to know if a product is profitable BEFORE you buy it
This is where most people go wrong: they buy first and do the math later. Run the full numbers before you spend a dime.
Profitability checklist
- Do you know what it sells for today on the marketplace where you'll sell it?
- At that price, after selling fees, shipping and taxes, do you clear your minimum margin?
- Is it small and lightweight? (cheaper to ship)
- Is it sturdy? (fewer breakages and returns)
- Is there proven demand? (listings with sales and reviews)
- Is the competition free of giant sellers dominating the space?
If you answer yes to most of these, it's worth digging deeper.
What Ficanaz shows you (and what it doesn't)
Ficanaz doesn't calculate your margin: it doesn't know your real cost, and without it any margin would be made up. What it does is give you the data so you can do the math yourself:
- Before you buy: in Research, with the "Validate my idea" mode, you see what MercadoLibre measures for the product in your country: when there are offers, the lowest price, plus the minimum and median price among the sellers offering it. The purchase cost shown is an AI estimate and is labeled as such: you set the real price with your supplier.
- Once you're selling: with your account connected, Sales shows your contribution by day or by SKU, meaning revenue minus the selling fees and shipping MercadoLibre charged you. Subtract your product cost and you've got your profit. In My listings, each listing's details show how much you billed and how much MercadoLibre charged you in selling fees.
Strategies to improve your margin
1. Negotiate with your supplier
Ask for volume discounts, better payment terms or shipping included.
2. Optimize your packaging
Smaller, lighter packaging lowers shipping costs. Don't use boxes bigger than you need.
3. Sell bundles
Instead of selling one unit, offer a 3-pack. Shipping gets spread across more units and your average order value goes up.
4. Stand out instead of cutting your price
If your product stands out (better photos, better description, better packaging, better service), you can hold a higher price. Don't always compete on price.
5. Cut down on returns
Clear photos, a detailed description and exact measurements. Every return eats into your margin.
Bottom line
Profit margin isn't "sale price minus product cost." It's a calculation with a lot of moving parts, and the difference between a profitable business and one that loses money is in the details.
Do the math BEFORE you buy. Include EVERY cost. And use your marketplace's real numbers instead of eyeballing it.
If you're just getting started, keep going with the guide to start selling on MercadoLibre.
Want to run the numbers with MercadoLibre data?
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