Contribution Margin Calculator
Find how much each unit you sell contributes toward fixed costs and profit. Enter a selling price and variable cost to get the margin per unit and the contribution margin ratio, then add the number of units and your fixed costs to see total contribution margin, profit, and the break-even point in units and revenue.
Formula
Worked example
A product sells for $50 with $30 of variable cost: margin = 50 - 30 = $20 per unit, ratio = 20 / 50 = 40%. With 1,000 units the total contribution margin is $20,000; after $12,000 of fixed costs that is $8,000 profit. Break-even = 12,000 / 20 = 600 units, or $30,000 in revenue.
What the contribution margin tells you
Contribution margin is the selling price of a unit minus the variable cost of producing and selling that unit. It is the amount each sale "contributes" toward covering your fixed costs, rent, salaries, insurance, and, once those are paid, toward profit. Unlike gross profit, which mixes in some fixed overhead, contribution margin isolates the costs that rise and fall directly with each unit sold, making it the cleanest measure of how much headroom a product gives you. Switch the cost entry to "Itemise the costs" to build the variable cost up from materials, direct labour, shipping, payment fees and commission, which is how most ecommerce and product teams actually track it.
Per unit, the ratio, and the totals
The dollar margin per unit is useful for break-even planning. The contribution margin ratio expresses that same margin as a percentage of price, so you can compare products of very different prices on a level field: a $5 candy bar and a $500 appliance might both run a 40% ratio. Add the number of units you expect to sell and the totals appear: total revenue, total variable cost, and the total contribution margin (margin per unit times units). Subtract your fixed costs from the total contribution margin and you have operating profit for the period. This is the contribution-margin form of a cost-volume-profit, or CVP, analysis.
Break-even and solving for a target profit
Break-even is the point where total contribution margin exactly equals fixed costs, so profit is zero. In units it is fixed costs divided by the per-unit margin; in revenue it is fixed costs divided by the contribution margin ratio. Selling one unit beyond break-even adds its full margin straight to profit. Turn on "Solve for a target profit" and the calculator works backwards: it adds your profit goal to fixed costs and divides by the margin to tell you how many units, and how much revenue, you need. The profit-versus-volume chart shows the same picture, a line that crosses zero at break-even and climbs by one margin for every extra unit.
Using it to make pricing and product decisions
Because the ratio strips out fixed costs, it answers a sharp question: of every dollar a customer pays, how much is left to fund the business? Products with higher ratios reach break-even sooner and absorb price competition better. When you weigh a discount, a new supplier, a higher shipping cost, or dropping a slow seller, recompute the contribution margin first. A discount that shaves the margin to near zero means you are selling effort for free, no matter how strong the headline revenue looks, and it pushes the break-even volume far higher.
How a contribution margin ratio reads
| CM ratio | Reading | What it usually means |
|---|---|---|
| Below 0% | Loss | Each sale loses money before any fixed cost |
| 0-30% | Thin | Low headroom, needs high volume to profit |
| 30-60% | Healthy | Typical for retail and manufacturing |
| Above 60% | Strong | Common in software and services |
A rough guide; healthy ratios vary widely by industry. Compare each product against your own others.
Frequently asked questions
What is the difference between contribution margin and gross profit?
Contribution margin subtracts only variable costs from price, while gross profit subtracts the full cost of goods sold, which can include some fixed manufacturing overhead. Contribution margin therefore isolates the per-unit profit available to cover all fixed costs and is the figure used for break-even and pricing analysis.
What counts as a variable cost?
Variable costs change directly with each unit you make or sell: raw materials, direct labour paid per unit, packaging, shipping, payment-processing fees, and sales commissions. Costs that stay the same regardless of volume, rent, salaried staff, insurance, are fixed and are not part of the contribution margin. Use the itemised mode to add these up.
How do I find the break-even point from the contribution margin?
Divide total fixed costs by the contribution margin per unit to get break-even units, or divide fixed costs by the contribution margin ratio to get break-even revenue. Below that level you lose money; above it, every extra unit adds its full margin to profit. This calculator shows both figures once you enter fixed costs.
How many units do I need to sell to reach a profit target?
Add your target profit to your fixed costs, then divide by the contribution margin per unit. Turn on "Solve for a target profit" and the calculator does this for you and also reports the revenue required, so you can sanity-check the volume against demand.
What is a good contribution margin ratio?
It varies widely by industry. Software and services often exceed 70% because their variable costs are tiny, while retail and manufacturing can run 20-40%. Rather than chase a universal number, compare each product against your own others and confirm the margin clears the fixed costs it needs to support.