Ecommerce profit margin: what it means and how to calculate it

Profit margin tells you how much of each dollar of net revenue remains after product cost. In ecommerce, that starts with net revenue — not list price — because discounts change the base you measure against.

Gross margin in plain language

When operators say profit margin, they often mean gross margin: gross profit divided by net revenue. Net profit margin after all operating expenses is a different finance metric. StoreOpps operational reports use gross margin on a net-revenue base.

The formulas

Net revenue = gross sales − discounts
Gross profit = net revenue − COGS
Gross margin = gross profit ÷ net revenue

A product sold at $80 after a $20 discount has $80 of net revenue, not $100. Skipping the discount step inflates margin.

What belongs in COGS

• Unit product cost for items sold in the period
• Inbound freight or duties allocated to product cost
• Packaging included in product cost records
• Not usually: payment fees, outbound shipping subsidies or marketing

Worked example

Reading the percentage

Higher gross margin is not automatically better if it suppresses volume or reflects a narrow mix. Compare margin to your own history, sales velocity and inventory — not generic industry tables alone.

Product-level margin

Store margin is a weighted average. A weak-margin bestseller can hide inside an acceptable headline number. Missing unit cost, zero net revenue lines or returns outside the export window can also distort SKU-level results.

From margin to action

• Rank products by margin and volume together
• Review cost updates on high-volume low-margin SKUs
• Test price on strong-margin items with low discount rates
• Recalculate margin after promotions, not from list price

Try it with your numbers

The StoreOpps calculator applies these formulas automatically when you enter gross sales, discounts and COGS for the same period.