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Profit Engineering™ · 12 min read

The Ultimate Contribution Margin Guide for Ecommerce Founders

If you only track one metric, track contribution margin per order. Here's the full breakdown.

Table of contents
  1. What contribution margin actually is
  2. The full formula
  3. Category benchmarks
  4. The 6 levers that move CM
  5. Modeling CM at scale
  6. FAQs

What contribution margin actually is

Contribution margin is what's left from a sale after all the variable costs that make that specific sale happen — before you get to fixed overhead.

It's the true unit economics of your business. Gross margin lies. ROAS lies. Contribution margin doesn't.

The full formula

CM per order = Selling Price − COGS − Shipping − Payment Gateway Fees − Returns Cost (allocated) − Marketing Cost per Acquired Order

Every variable matters. Miss one, and your CM is fiction.

Example: Skincare brand

  • Selling price: ₹1,299
  • COGS: ₹310
  • Shipping (allocated): ₹70
  • Payment gateway: ₹29
  • Returns allocation: ₹80
  • Marketing per order: ₹410

CM per order = ₹400 (30.8%)

Healthy. Room to scale.

Category benchmarks

  • Skincare: 25–35%
  • Fashion / Apparel: 15–25%
  • Supplements: 30–45%
  • Electronics: 12–22%
  • Beauty: 20–32%

The 6 levers that move CM

  1. Pricing power (positioning, bundles)
  2. COGS reduction (sourcing, volume)
  3. Shipping optimization (mix, weight, zones)
  4. RTO reduction (Anti-RTO Engine™)
  5. AOV lift (upsells, thresholds)
  6. CAC reduction (creative, funnel, retention)

Modeling CM at scale

Build a per-SKU CM model. Then aggregate weighted by mix. Then stress-test at different spend levels. This is your growth compass.

FAQs

Q: Difference between gross margin and CM?

Gross margin is Revenue − COGS. CM is Revenue − all variable costs including marketing, shipping, returns. CM is the truth.

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