Free Tools/Contribution Margin Calculator

Contribution Margin Calculator

Calculate your true per-unit profitability. Enter your selling price and all variable costs to see your contribution margin and break-even volume.

Unit Economics

Selling Price

Cost of Goods Sold (COGS)

Shipping Cost per Unit

Payment Processing Fee (%)

Platform / Marketplace Fee (%)

Ad Cost per Unit

Monthly Fixed Costs (for break-even calculation)

Contribution Margin

per unit

Margin Percentage

Break-even Units / Month

Contribution Margin Benchmarks

Healthy ecommerce margin25% - 50%

DTC brands (average)30% - 40%

Marketplace sellers (Amazon, etc.)15% - 30%

SaaS products70% - 90%

Below 15%Risky — very little room for error

What is Contribution Margin?

Contribution margin is how much money you keep from each sale after subtracting all variable costs — COGS, shipping, payment processing fees, platform fees, and ad spend per unit. It is the amount each sale contributes toward covering your fixed costs and generating profit.

Formula: Contribution Margin = Selling Price - Total Variable Costs per Unit

This is the most important metric for ecommerce founders. Revenue means nothing if your variable costs eat all of it. A $100 product with a 10% contribution margin only gives you $10 to cover rent, software, salaries, and everything else.

Track contribution margins across all your products automatically

Kartib connects to Shopify and calculates margins per product, per channel, and per month. See the full picture.

Start for Free