Unit economics calculator for an online shop or marketplace seller
Enter price, costs, commission, advertising and returns for one product. The sheet works out profit per order, margin and break-even orders, and compares products.
This is a spreadsheet for checking whether one sale of a product leaves money after everything that sale costs you. It is for the owner of a small online shop and for a marketplace seller who sets prices alone and has no finance person to ask. Use it before you order a new batch, before you launch advertising for a product, and each time a platform changes its commission or delivery rates. You enter twelve numbers for one product. The sheet works out profit per order, margin and the number of orders a month that cover fixed costs, and compares several products side by side. Every number in the file is an example and has to be replaced with your own.
What is inside
- Sheet "How to use": seven steps and every term explained in one line.
- Sheet "One product": twelve inputs, one per row, each with a unit and a comment on where to get the number.
- Ten result rows calculated by formulas: commission, payment fee, advertising and return cost per order, tax, total variable cost, profit per order, margin, break-even orders, profit per month.
- Sheet "Compare": up to six products in one table, with profit per order, margin and monthly profit before fixed costs.
- A filled-in example in US dollars, labelled as an example, so you can see how the numbers move before entering your own.
- Formulas use only IF and ROUND, so the file is meant for Excel, Google Sheets, Numbers and LibreOffice Calc.
How to use it
- Open the sheet "One product" and replace the example in column B, rows 3 to 14, with the numbers for one of your products. Keep one currency for every money row.
- Take the commission, payment fee and delivery rate from your own seller account or the platform's current tariff page. The percentages in the file are examples, not anyone's real rates.
- Enter last month's advertising spend for this product and the number of orders customers kept. Then enter the share of orders that come back and what one return costs you.
- Leave the tax rate at 0, or enter your own if your tax is counted as a percent of revenue. If you are not sure which rate applies to you, ask your accountant.
- Read rows 16 to 25. Start with profit per order, then margin, then break-even orders per month. Change one input at a time to see which one moves the result most.
- Go to the sheet "Compare", replace the example rows with your products and see which ones earn money on every order and which only look good on price.
How to read the result
Profit per order is the first number to look at. It is the price minus everything one order costs: the goods, packaging, commission, payment fee, delivery, its share of advertising, its share of returns and tax. If it is zero or negative, selling more does not help: every extra order adds to the loss. The cure is in the inputs, not in the volume.
Margin puts the same profit next to the price. The product in the example leaves $5.33 from a $30 sale, a margin of 17.8%. That number tells you how much room there is for a discount or a rate change before the sale stops paying for itself. Break-even orders answers a different question: with this profit per order, how many orders a month pay for the costs that do not depend on orders. Compare it with the orders you really get.
| What you see | What it means | What to check next |
|---|---|---|
| Profit per order is negative | Each sale costs more than it brings in. | Price, cost of goods and delivery first; then whether advertising for this product pays at all. |
| Profit per order is positive, margin is a few percent | The sale pays for itself only while every input stays where it is. | Raise the return share by a few points and the commission by one point and see whether any profit is left. |
| Break-even orders are above your current orders | One sale earns money, but the month as a whole does not cover fixed costs yet. | Whether more orders are realistic at the same advertising cost per order, or whether fixed costs can be lower. |
| Profit per month is positive | At these numbers the product covers its own costs and the fixed costs you entered. | Enter the rates again next month: commissions, delivery prices and advertising cost per order do not stand still. |
Why advertising and returns are the two inputs people forget
Cost of goods, commission and delivery sit on an invoice or in a tariff table, so they are hard to miss. Advertising and returns arrive differently. Advertising is paid as a monthly budget, not order by order, and it is easy to treat it as a general expense of the business rather than a cost of each sale. Divide the month's spend by the orders it brought and it can turn out to be one of the largest lines in the calculation. In the example it is $5.00 per order: more than delivery and more than the commission.
Returns are forgotten because they happen later and seem to belong to some other order. A returned parcel has already used up delivery to the customer, then costs delivery back and repacking, and the payment provider may keep its fee. The orders that customers keep have to carry that cost. The sheet spreads it this way: if 8 of 100 orders come back, each of the 92 that stay carries 8/92 of the cost of one return. At a low return share the line is small. At 30% or more it can decide whether the product makes money, which is why the sheet asks for both numbers separately.
- Count advertising for the same period as the orders: one month of spend against the orders of that month.
- If some orders come without advertising, enter all the orders customers kept. The result is then an average across paid and free orders, which is the honest figure for the product as a whole.
- Take the return share from your own order history, not from a guess. With a new product, try a low value and a high one and look at both results.
What the sheet does not include
The calculator looks at one order in one month. It leaves out three things that can weigh as much as the lines it has. Add them by hand where they apply to you.
It also treats advertising cost per order and the return share as steady. Both move when you scale, so take break-even orders as a level to test, not as a forecast.
- Stock financing. Money tied up in goods that are paid for and not yet sold, and interest if the batch was bought on credit.
- Storage fees by volume. A warehouse or a marketplace may charge for the space and the days an item occupies; a bulky slow seller costs more to keep than the sheet shows.
- Currency risk. If you buy in one currency and sell in another, the cost of goods moves with the exchange rate between paying the supplier and selling the item.
Questions
Which tax rate should I enter?
The sheet assumes no tax, so the cell starts at 0. If your tax is counted as a percent of revenue, enter that percent. If you pay tax on profit, leave 0 and remember that the profit shown is before tax. The rate depends on your country and tax regime: take it from your accountant or the tax authority, not from this file. If you charge VAT or sales tax on top of the price, enter the price and the costs without it.
My platform charges a fixed fee per order, not a percent. Where does it go?
Add it to the delivery cost per order in row 8 or to packaging in row 5: both rows are amounts per order in your currency. The commission and payment fee rows take percentages only. If a fee has a percent part and a fixed part, put the percent in row 6 or 7 and the fixed part in row 8.
Can I use it if I sell without advertising?
Yes. Enter 0 as advertising spend and your usual number of orders per month in row 10. The advertising line becomes 0 and the monthly profit is still calculated from the orders you entered.
Does the file work in Google Sheets and Numbers?
It is a regular .xlsx file and the formulas use only IF and ROUND, functions that Excel, Google Sheets, Numbers and LibreOffice Calc all have. Upload it to Google Drive or open it in Numbers as you would any other spreadsheet.