Contribution margin isolates the profit each unit contributes toward fixed costs. This calculator builds a contribution-format income statement and quantifies operating leverage — how much operating income moves for a given change in volume.
How it works
Build a contribution-format income statement and measure how sensitive operating income is to changes in sales volume.
Contribution margin = Sales − Variable costs
CM ratio = Contribution margin ÷ Sales
Operating income = Contribution margin − Fixed costs
Degree of operating leverage (DOL) = Contribution margin ÷ Operating income
% change in operating income ≈ DOL × % change in salesCommon uses
- Product and service-line profitability
- Make-or-buy and special-order decisions
- Sensitivity of earnings to volume
Worked example
The calculator above opens with this example. Change any input to see the results update instantly, or select Reset to return to these figures.
| Selling price per unit | $120 |
| Variable cost per unit | $68 |
| Units sold | 30,000 |
| Fixed costs (period) | $1,050,000 |
| Sales volume change to test | 10% |
| Contribution margin ratio | 43.3% |
| Contribution margin / unit | $52.00 |
| Operating income | $510,000 |
| Degree of operating leverage | 3.06× |
| Operating income at 10.0% volume | $666,000 |
Each 1% change in sales volume changes operating income by about 3.06%.
Interpreting the results
- High DOL means profits rise quickly with volume but fall just as quickly in a downturn.
- DOL is highest near break-even and declines as volume grows above it.
- Use the CM ratio, not gross margin, for short-term pricing and volume decisions.
Frequently asked questions
What is the difference between contribution margin and gross margin?
Gross margin deducts cost of goods sold, which can include fixed production overhead. Contribution margin deducts only variable costs — including variable selling costs — so it shows how profit responds to volume.
What does degree of operating leverage mean?
Degree of operating leverage (DOL) equals contribution margin divided by operating income. A DOL of 3.0× means a 10% change in sales volume produces roughly a 30% change in operating income, in either direction.
Is a higher contribution margin ratio always better?
A higher ratio means each sales dollar covers more fixed cost, but it often accompanies a higher fixed-cost base and therefore higher operating leverage and risk. Evaluate it together with the fixed-cost structure and the stability of demand.
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