About the Contribution Margin Calculator
The contribution margin is what each sale adds towards covering fixed costs and then profit. This calculator takes the selling price, the variable cost per unit and the fixed costs, and gives the margin per unit, the ratio, the number of units to break even and the sales value at that point. If you add the units you expect to sell, you also get the profit and the margin of safety. Type the price, variable cost, fixed costs and expected units and the contribution margin appears at once, with a few related figures underneath, and you can copy the result with one tap. The sums run in your browser, so nothing you enter is uploaded.
Updated October 2026
How to use the Contribution Margin Calculator
- 1Enter the price, variable cost, fixed costs and expected units.
- 2Pick the units or options from the menus if the contribution margin tool offers them.
- 3Read the contribution margin in the large result box.
- 4Look at the extra rows for related figures.
- 5Press Copy result to keep the answer.
When you need the contribution margin
Small business owners use it to set prices and to decide whether a product pays its way. Accountants use it in cost-volume-profit analysis.
A higher ratio means a smaller sales volume is needed to break even. The margin of safety shows how far sales can fall before you start losing money.
How the contribution margin is worked out
Contribution margin = price − variable cost per unit. Ratio = margin ÷ price. Break-even units = fixed costs ÷ margin. Profit = units × margin − fixed costs. A product sells for 50 with a variable cost of 30, so each unit contributes 20 (a 40% ratio). With fixed costs of 20,000, break-even is 1,000 units, or 50,000 in sales. At 1,500 units, profit is 10,000.
Every answer on this page comes from that one rule, so you can check any result by hand with a calculator. The figures shown underneath, such as other units, are conversions of the same answer.
- Break-even in units and sales
- Profit at expected volume
- Margin of safety
Mistakes to avoid with contribution margin
Only variable costs belong in the unit cost: materials and commission that change with each sale. Rent and salaries are fixed costs. If the price is not above the variable cost, no volume can cover the fixed costs.
On phone and computer
On a phone, type into the boxes one after another and read the contribution margin underneath; Copy result puts it on the clipboard for a message or a note. On a computer the inputs sit on the left and the answer on the right, so you can change one figure and watch the contribution margin move. The contribution margin calculator works the same on both.
Checking your contribution margin by hand
A good habit is to test the contribution margin calculator with a case you already know. A product sells for 50 with a variable cost of 30, so each unit contributes 20 (a 40% ratio). With fixed costs of 20,000, break-even is 1,000 units, or 50,000 in sales. At 1,500 units, profit is 10,000.
If your own figures give a surprising answer, repeat the working yourself: Contribution margin = price − variable cost per unit. Ratio = margin ÷ price. Break-even units = fixed costs ÷ margin. Profit = units × margin − fixed costs. Small differences usually come from rounding, from mixing units, or from a typing slip in one of the inputs. Contribution margin tells you what each sale leaves after variable costs. Use that figure in the Break-Even Calculator to find the sales you need, judge a return with the ROI Calculator, and see how fast stock sells with the Inventory Turnover Calculator.
Features
- Only variable costs go in unit cost
- Price must beat variable cost
- Fixed costs stay the same per period
- Clear messages when the contribution margin inputs make no sense
- Copy the result with one tap
- Private: nothing is uploaded
Frequently asked questions
How do I calculate contribution margin?
Contribution margin = price − variable cost per unit. Ratio = margin ÷ price. Break-even units = fixed costs ÷ margin. Profit = units × margin − fixed costs. A product sells for 50 with a variable cost of 30, so each unit contributes 20 (a 40% ratio). With fixed costs of 20,000, break-even is 1,000 units, or 50,000 in sales. At 1,500 units, profit is 10,000.
What is the formula for contribution margin?
Contribution margin = price − variable cost per unit. Ratio = margin ÷ price. Break-even units = fixed costs ÷ margin. Profit = units × margin − fixed costs. The contribution margin calculator applies it exactly and rounds only the displayed answer to six significant figures.
How is it different from gross margin?
Gross margin uses cost of goods sold, which may include fixed production costs.
What is the margin of safety?
The share of expected sales above the break-even point.
Can the contribution margin be negative?
Yes, if the price is below the variable cost, and then each sale loses money.
Is this contribution margin calculator free and private?
Yes. It is free, needs no account and runs in your browser, so the numbers you type are not uploaded or stored.