# Ecommerce Contribution Margin

> Contribution margin is net order revenue minus the variable costs required to generate and serve that order. It shows what remains to cover fixed costs and profit, and it is a more accurate measure of order-level economics than gross margin because it includes fulfillment, payment and other variable costs that gross margin excludes.

- Type: Merchant guide
- Level: Intermediate
- Reading time: About 6 minutes
- Audience: Written for store owners, builders, and designers refining high-performance ecommerce stores.
- Last updated: 2026-11-04
- Canonical page: https://academy.getzenbasket.com/merchant-questions/ecommerce-contribution-margin/
- Part of: [Merchant Questions](https://academy.getzenbasket.com/merchant-questions/) on ZenBasket Academy

---

## What you need to know

### What is contribution margin in ecommerce?

Contribution margin is net order revenue minus the variable costs required to generate and serve that order. It shows what remains to cover fixed costs and profit.

### Gross margin vs contribution margin: what's the difference?

Gross margin subtracts cost of goods sold from net sales; contribution margin also subtracts defined variable costs such as payment fees, fulfillment, shipping subsidy, returns and possibly marketing.

### How do I calculate contribution margin per order?

Begin with net order revenue, including separately defined shipping income, then subtract COGS and every variable order cost in the reporting policy. Label whether marketing and expected return cost are included.

### Why should merchants measure profit per order?

Profit per order reveals whether sales cover the costs they create and which products, discounts or channels weaken economics. Store-level averages can hide many loss-making orders.

### Can free shipping make profitable orders unprofitable?

Yes. When the merchant absorbs shipping and related fulfillment cost, an order that was profitable before shipping can become unprofitable. Evaluate the threshold using contribution distribution.

### Can discounts increase sales but reduce contribution margin?

Yes. Discounts may produce more orders while reducing contribution on each discounted order and shifting full-price demand. Judge incremental total contribution, not sales volume alone.

### A quick store check

Calculate contribution for a normal order, a discounted order and a free-shipping order using the same cost rules.

---

## Frequently asked questions

### Can contribution margin be negative on a completed order?

Yes. Discounts, product cost, payment fees, fulfillment, shipping subsidy and returns can exceed net order revenue.

### Should contribution include advertising cost?

State the level: pre-marketing contribution excludes it, while post-marketing contribution includes attributable acquisition cost.

---

## Related learning path

- **Ecommerce Profitability Analytics**
- **Ecommerce Marketing Economics**
- [ZenBasket Build Guide](https://help.getzenbasket.com/zenbasket-builder/)