Contribution Margin

Q: How do you calculate CM?

Contribution Margin = (Revenue - All Variable Costs) / Revenue × 100

The profit earned on each unit sold after deducting all variable costs.

1 min readLast updated Apr 2026

Reviewed by Golden Digital·Operator-reviewed ecommerce reference·Benchmark source: Golden Digital field data

Formula

Contribution Margin=(Revenue - All Variable Costs)/Revenue × 100

Example: Variable costs = $18 + $8 + $6 + $12 = $44. CM = ($60 - $44) / $60 = 26.7%

The profit earned on each unit sold after deducting all variable costs.

Use our free Contribution Margin Calculator to see what each order leaves you after product, shipping, fees, returns and ads.

Why It Matters

Contribution margin is the most honest measure of per-order profitability because it includes ALL variable costs, not just COGS. It tells you exactly how much each sale contributes to covering your fixed costs and generating profit. This clarity is essential for making pricing, promotion, and marketing spend decisions.

Formula

Contribution Margin=(Revenue - All Variable Costs)/Revenue × 100

Example: Variable costs = $18 + $8 + $6 + $12 = $44. CM = ($60 - $44) / $60 = 26.7%

Benchmarks

A good CM is 30-40%. Top performers achieve 40%+.

Good Performance

30-40%

Top Performers

40%+

Practical Example

Scenario

A pet food brand sells a $60 subscription box. Variable costs: $18 COGS, $8 fulfillment, $6 payment processing, $12 marketing (allocated).

Calculation

Variable costs = $18 + $8 + $6 + $12 = $44. CM = ($60 - $44) / $60 = 26.7%

Result

With 26.7% contribution margin, each box contributes $16 toward fixed costs. They need to sell 625 boxes/month to cover $10,000 in fixed costs, then every additional sale is profit.

In-Depth Explanation

Counts more costs than gross margin—D2C brands should aim for 30-40% contribution margin.

Pro Tips

1Calculate CM per SKU, not just blended. Hero products often subsidize poor performers—know which products actually make money.
2Use CM to evaluate promotions. A 20% discount on a 35% CM product drops you to 15% CM—know your floor before offering discounts.
3Include payment processing fees (2.5-3%) in variable costs. Many brands forget this and overstate margins.
4Track CM by channel. Subscription customers often have higher CM due to lower marketing cost per order.

Common Mistakes to Avoid

Confusing contribution margin with gross margin. Gross margin only subtracts COGS; CM includes fulfillment, transaction fees, and sometimes marketing.

Not including shipping costs in CM calculation for 'free shipping' orders. Free shipping isn't free—it's a variable cost you're absorbing.

Using average CM when SKU-level variance is high. A 40% blended CM might hide that your hero product is 60% and accessories are 15%.

Frequently asked questions

Gross margin = Revenue minus COGS only. Contribution margin = Revenue minus ALL variable costs (COGS + fulfillment + transaction fees + variable marketing). CM gives you the true per-order profit that contributes to covering fixed costs.

Aim for 30-40%+ after all variable costs. Below 25%, you need very high volume or extremely low fixed costs to be profitable. Above 40% gives you flexibility for growth investment and weathering slow periods.

It depends on how you allocate them. CM1/CM2/CM3 methodology excludes marketing until CM3. If you allocate marketing per order (e.g., via CAC/orders), you can include it. Be consistent in your approach.

Put it to work

Related Terms

Gross Margin

The percentage of revenue remaining after subtracting the cost of goods sold (COGS).

Contribution Margin 1, 2, 3

A layered contribution margin analysis: CM1 (Revenue minus COGS), CM2 (CM1 minus fulfillment), CM3 (CM2 minus marketing).

Customer Acquisition CostCAC

The total cost of acquiring a new paying customer, including all marketing and sales expenses divided by the number of new customers acquired over a specific period.

Return On Ad SpendROAS

The revenue generated for every dollar spent on advertising.

Calculate Yours

Calculate your CM in seconds.

Enter order value and every per-order cost. See what is left after product, shipping, payment fees, returns and ad spend, and which cost takes the biggest bite. Calculator results are available without an account.

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7.7x blended return at scale — seven figures attributed, across five straight quarters · Modern Prairie · Apr 2025–Jun 2026 Read the Modern Prairie case study