How to Calculate E-commerce Profit: Complete Guide + Formula
Revenue tells you how much customers paid. It does not tell you whether a product made money. A $50 order can still lose money once you subtract product cost, shipping, packaging, payment processing, platform fees, advertising, and the orders that come back.
This guide walks through the profit formula sellers actually need, then explains how Profit For Sellers turns those pieces into expected profit per order, margin, monthly net profit, break-even CPA, and break-even ROAS. The worked example uses the same engine and default scenario as the E-commerce Profit Calculator. For the site-wide rules behind that math, see methodology.
Revenue vs profit
Gross revenue for an order is the money the customer is charged for that order: the selling price plus any shipping you collect from them. If the item is $50 and shipping charged to the customer is $0, gross revenue is $50. If you charge $8 for shipping, gross revenue is $58.
Profit is what remains after costs. Those two numbers answer different questions. Revenue answers “how large was the order?” Profit answers “after the costs attached to that order, did we keep anything?” Treating revenue as profit hides every cost that scales with sales: inventory, pick and pack, labels, card processing, ads, and returns.
The basic profit formula
The starting identity is simple:
Profit = Revenue − Total costs
The hard part is defining total costs honestly. Many sellers stop at cost of goods sold (COGS): what they paid the supplier for the unit. That is a real cost, and it is not enough. An order that clears COGS can still lose money on fulfillment, payment fees, marketplace fees, advertising, packaging, and refunds.
For planning an online catalog, it is usually more useful to estimate profit on an expected-order basis: the average result across successful deliveries and refunded orders, using a refund rate and explicit assumptions about which costs you still lose when a customer is refunded.
Cost components that belong in an e-commerce profit calculation
The E-commerce Profit Calculator treats the following as separate inputs. You do not have to use every field, but skipping one that you actually pay will overstate profit.
Product cost / COGS
What you pay for the unit itself: supplier invoice, landed cost if you already rolled inbound freight into unit cost, or manufacturing cost. If inbound freight is billed separately per order, put it in fulfillment instead of double-counting it here.
Customer-paid shipping revenue
Shipping charged to the customer is revenue, not a cost. It increases gross revenue and, in this model, also increases percentage-based payment and platform fees. A “free shipping” offer simply means this input is zero; you still pay fulfillment.
Fulfillment and shipping cost
What you pay to get the package to the customer: postage, pick and pack, 3PL fulfillment fees, or outbound freight. This is independent of whether the customer reimbursed you.
Packaging
Boxes, mailers, tape, inserts, and branded packaging. Small per order, easy to ignore, and still real cash.
Payment processing percentage
The percentage of gross order revenue taken by the payment processor or checkout. In this calculator, the percentage applies to selling price plus shipping charged. Enter the rate you actually pay; this tool does not publish a processor fee schedule.
Payment processing fixed fee
The per-transaction amount many processors add on top of the percentage, such as a few cents per charge. It is applied once per order in this model, even if the selling price is low. Leaving it out overstates profit on cheap items.
Marketplace / platform fees
An optional percentage of gross revenue for marketplace commission, referral fees, or similar. The E-commerce Profit Calculator does not auto-fill marketplace rate cards. If you sell on Shopify and want United States plan payment presets, use the Shopify Profit Calculator instead of inventing a blended rate here.
Advertising cost per order
What you spent to acquire that order, typically campaign spend divided by orders (CPA). In this model, advertising is treated as already spent on refunded orders as well. A return does not give the ad dollar back.
Refunds and returns
Enter the share of orders you expect to refund. The calculator does not simply subtract “refund rate × revenue” from an otherwise perfect order. It mixes a successful-order outcome with a refunded-order outcome. Details are in the model section below.
Other variable costs
Anything else that moves with the order: extra pick fees, inserts, payment-on-delivery charges you bear, or a tax amount you choose to model yourself. The calculator does not estimate sales tax, VAT, or income tax.
Fixed monthly operating expenses
Rent, salaries, software, photography retainers, and similar overhead. In this model they change monthly net profit only. They are not allocated into profit per order, margin, or break-even CPA. Mixing them into per-order costs by hand will make those per-order metrics mean something different from what the calculator shows.
How the E-commerce Profit Calculator models profit
The definitions below match the production calculator. Percentages you type in the UI (for example 2.9% or 5%) are converted to decimal fractions before the formulas run. Currency symbols are display only; they do not change the math.
Gross revenue
Successful-order profit
Refunded-order profit
Expected profit per order
Expected revenue after refunds
Profit margin
Monthly net profit
Break-even CPA
Break-even ROAS
Worked example
These figures are an illustration, not recommended prices or fees. They come from the calculator’s default example: selling price $50.00, shipping charged $0.00, product cost $15.00, fulfillment shipping $5.00, packaging $1.00, payment fee 2.9% + $0.30, platform fee 0%, advertising $12.00 per order, 5% refund rate, 100 orders per month, no monthly fixed expenses, and conservative 100% cost-loss on refunds.
| Step | Result |
|---|---|
| Gross revenue | $50.00 |
| Payment fee (2.9% of $50 + $0.30) | $1.75 |
| Successful-order profit | $15.25 |
| Refunded-order profit | -$34.75 |
| Expected profit per order (95% successful + 5% refunded) | $12.75 |
| Expected revenue after refunds | $47.50 |
| Profit margin | 26.8% |
| Break-even CPA | $24.75 |
| Break-even ROAS | 1.92x |
| Monthly net profit at 100 orders, no fixed expenses | $1,275.00 |
Read the successful-order line first: $50.00 − $15.00 product − $5.00 fulfillment − $1.00 packaging − $1.75 processing − $12.00 ads = $15.25. That is the kept-order result. A refunded order, under the default full-loss assumptions, keeps no revenue and still bears product, fulfillment, packaging, processing, and ads, for -$34.75.
Average those outcomes at a 5% refund rate and you get $12.75 expected profit per order, not $15.25. Expected revenue is $47.50 because 5% of the $50.00 is refunded. Margin is therefore 26.8% of retained revenue, not of the original ticket.
Before ads, the same mix leaves $24.75 of expected contribution. That is the most you can spend on advertising per order and still expect to break even. Divide expected revenue by that CPA and break-even ROAS is 1.92x. Spending $12.00 per order is below that ceiling, which is why the example is profitable.
Monthly net profit at 100 orders and no overhead is $1,275.00. If the same product also had $400.00 of monthly fixed expenses, monthly net profit would fall to $875.00. Per-order expected profit would still be $12.75, because overhead is not allocated into that line.
What is a good e-commerce profit margin?
There is no universal “good” margin that applies to every product. A number that looks healthy for a handmade item sold on a small organic audience can be unworkable for a paid-traffic commodity SKU with a high return rate. Treat published industry averages with caution unless you know the definition of margin, which costs were included, and whether advertising and refunds were in the denominator.
What counts as acceptable depends on at least:
- Product category and replacement cost. Low-ticket consumables and high-ticket durables do not share a single target.
- How you acquire customers. Paid social and search consume contribution profit that organic or repeat buyers do not.
- Refund and return rates. Categories with try-on or “not as described” risk need more contribution on the orders that stick.
- Operating structure. A seller with warehouse rent and payroll needs more contribution per order than a seller whose only fixed cost is a storefront subscription.
- Growth strategy. Reinvesting contribution into ads or inventory can make net profit small on purpose while unit economics remain sound—or hide a product that never covered variable costs.
Use your own break-even CPA and expected profit per order as the test, not a borrowed percentage. If expected profit is negative before you scale spend, a higher “target margin” on a spreadsheet will not fix it.
Gross margin, contribution profit, and net profit
Sellers often use “margin” for three different leftovers. Mixing them is one of the fastest ways to think a product is fine when it is not.
- Gross margin usually means revenue minus product cost (sometimes minus inbound freight), divided by revenue. It ignores ads, processing, packing, and returns. A 70% gross margin can still lose money after those costs.
- Contribution profit / contribution margin is what remains after variable costs that move with the order. In this calculator, expected profit per order is a contribution figure after product, fulfillment, packaging, fees, ads, other variable costs, and expected refunds. The reported profit margin is that contribution divided by expected retained revenue.
- Net profit is what remains after contribution and fixed operating expenses. Here that is monthly net profit: contribution across the month minus monthly fixed expenses. It still is not accounting profit after taxes unless you entered those costs yourself.
When someone asks “what’s your margin?”, ask which of the three they mean, and whether refunds and ads are inside the number.
Why profitable products can still lose money
A SKU that looks profitable in last month’s snapshot can lose money when one input moves and the others stay put. Common paths:
- Advertising gets more expensive. If CPA rises above break-even CPA, expected profit per order crosses to a loss even when the product, price, and fees did not change.
- Refund rates increase. Each extra refunded order can still consume product, shipping, packaging, fees, and ads. A small rate change has a large effect when the refunded-order loss is several times the successful-order profit.
- Fulfillment costs rise. Carrier or 3PL increases cut contribution on every order, kept or not, under full-loss return assumptions.
- Payment or platform fees. Percentage fees scale with price and with shipping charged. A price increase does not pass through one-for-one.
- Fixed overhead. Positive contribution per order can still fail to cover rent, tools, and payroll. That shows up in monthly net profit, not in the per-order line.
- Discounting without recalculating. A 20% off sale cuts revenue immediately and also changes percentage fees. Costs such as COGS, packing, and CPA often stay the same. Re-run the price through the Product Pricing Calculator or this profit model before you advertise the discount.
Common e-commerce profit calculation mistakes
- Treating revenue as profit. Sales reports are not income.
- Ignoring processing fees. The percentage applies to gross revenue, including shipping you collect.
- Forgetting the fixed transaction fee. A $0.30 fee is 6% of a $5 add-on and 0.6% of a $50 item. It is not optional on low-priced SKUs.
- Ignoring refunds. Subtracting a refund percentage from revenue understates the damage if you still lose product, shipping, ads, and fees.
- Ignoring advertising. Organic screenshots of “product margin” do not survive paid acquisition.
- Forgetting packaging and fulfillment. Free shipping is a cost decision, not a missing line.
- Mixing monthly fixed expenses into per-order costs incorrectly. Dividing rent by last month’s order count and stuffing it into COGS makes every per-order metric depend on volume. This calculator keeps overhead on the monthly net line so contribution stays comparable across SKUs.
- Calculating ROAS without contribution economics. A 3x ROAS can be a loss if contribution before ads is thin. Compare reported ROAS to break-even ROAS from this model, the Break-Even ROAS Calculator, or how to calculate the ROAS you need to be profitable, using the same revenue definition.
Related tools
Use the E-commerce Profit Calculator for expected profit, margin, break-even CPA, and break-even ROAS from a known advertising cost per order. To solve the advertising multiple itself, see Break-Even ROAS. Store-specific United States Shopify payment presets live on the Shopify Profit Calculator. To solve a selling price from a target margin, use the Product Pricing Calculator or How to Price a Product for Profit. Assumptions and fee-source rules for the whole site are on the methodology page.