Empire AI Finance
Contribution Margin
The profit each sale contributes before fixed costs. Learn how to calculate contribution margin per unit, as a ratio, and why it shapes pricing and product decisions.
Contribution Margin Calculator
Your Numbers
Selling price before VAT.
Direct materials, labour, shipping, commissions.
Leave blank to see per-unit and ratio only.
Contribution Margin per Unit
£0.00
Contribution Margin Ratio
0.00%
What Contribution Margin Means
Contribution margin is the amount each sale contributes toward covering fixed costs and then generating profit. It is calculated by subtracting the variable cost of a product or service from its selling price.
Unlike net profit, contribution margin ignores fixed costs such as rent and salaries. This makes it especially useful for decisions about pricing, product mix and break-even analysis.
Contribution Margin Formula
Per Unit
Contribution Margin = Price − Variable Cost
The cash left from one sale after covering the variable costs directly tied to that sale.
Ratio
CM Ratio = (Contribution Margin ÷ Price) × 100
The percentage of each sale that contributes to fixed costs and profit. Useful for comparing products with different prices.
Worked Example
A business sells a product for £120 per unit. The variable cost per unit — materials, packaging and delivery — is £72. It sells 500 units.
Contribution Margin = £120 − £72 = £48
CM Ratio = (£48 ÷ £120) × 100 = 40%
Total Contribution = 500 × £48 = £24,000
Contribution Margin vs Gross Margin
| Aspect | Contribution Margin | Gross Margin |
|---|---|---|
| Costs deducted | Only variable costs | Full cost of goods sold |
| Focus | Per-unit contribution to fixed costs | Overall production profitability |
| Includes fixed production costs | No | Yes, if part of COGS |
| Best used for | Pricing and product-mix decisions | Reporting and benchmarking |
| Formula | Price − Variable Cost | Revenue − COGS |
Use Cases
Pricing Decisions
See how much room you have to discount without making each sale unprofitable at the variable-cost level.
Product Mix
Compare contribution margins across products to decide which lines to promote, expand or retire.
Break-Even Analysis
Divide fixed costs by contribution margin per unit to find the number of sales needed to break even.
Special Orders
Evaluate one-off orders by comparing the offered price to the variable cost, ignoring allocated fixed costs.
Mini-FAQ
What is contribution margin?
Contribution margin is the revenue left after deducting variable costs. It shows how much each sale contributes toward covering fixed costs and generating profit.
How do you calculate contribution margin?
Contribution margin per unit equals selling price minus variable cost per unit. The contribution margin ratio is contribution margin divided by selling price, multiplied by 100.
What is the difference between contribution margin and gross margin?
Contribution margin only deducts variable costs. Gross margin deducts the full cost of goods sold, which may include both variable and fixed production costs.
Why is contribution margin useful?
It helps with pricing, break-even analysis and product mix decisions. It shows whether each additional sale covers its own variable costs and contributes to fixed overheads.
Can contribution margin be negative?
Yes. If variable costs exceed the selling price, the contribution margin is negative. Every sale then loses money before fixed costs are considered.
Founder Vision
Empire AI Finance exists to make financial concepts practical. Contribution margin is one of the most powerful tools for founders because it strips away fixed costs and reveals the true economics of each sale.
Our calculators help you model price changes, compare products and make decisions grounded in real numbers.
Trust & Safety
Empire AI Finance is a software and analysis platform. We do not provide financial advice, manage money, execute trades, hold deposits or promise investment returns. The information on this page is for educational and informational purposes only.
For decisions affecting your business, tax position or legal obligations, consult a qualified accountant or legal professional familiar with your jurisdiction.
What Empire AI Finance Does Not Provide
Financial Advice
We do not give personalised financial, investment, tax or legal advice. Our outputs are generated by software for informational purposes.
Trading or Brokerage
We do not execute trades, hold securities, or operate an investment platform. Empire AI Finance is a software toolset, not a broker-dealer.
Deposit-Taking or Custody
We never request, receive or hold client funds, cryptocurrencies or assets. All payments go through secure third-party checkout providers.
Promises of Returns
We do not guarantee profits, savings, valuations or business outcomes. Any examples shown are illustrative, not typical or guaranteed.
Explore the full toolkit
From contribution margin and break-even to gross profit and net margin, Empire AI Finance gives you the calculators and explainers to understand your numbers with clarity.
Last updated: 23 October 2026