6 Reasons Your Break-Even Number Is Wrong
Sam's List Editorial | 2026-07-31
6 Reasons Your Break-Even Number Is Wrong Most break-even numbers are too low, and they are too low in a predictable direction. The formula itself is simple: fixed costs divided by contribution margin per unit, or for a mixed revenue business, fixed costs divided by the contribution margin ratio. The break-even analysis mistakes below are not errors in the arithmetic. They are errors in what gets fed into it, and every one of them produces a number that makes the business look like it clears the bar sooner than it does. Here are the six, and then a worked example of what they cost together. 1. Using Gross Revenue Instead of Contribution Margin This is the most common error and the largest. Dividing fixed costs by revenue treats every dollar of sales as if it were available to cover overhead. It is not. The dollars that go out again as materials, direct labor, subcontractors, shipping and payment processing never touch your fixed costs. If your contribution margin is 45 percent, then covering 30,000 of fixed costs requires roughly 66,700 in revenue, not 30,000. Owners who use revenue as the denominator are off by a factor equal to their margin, which for most service and product businesses means the real break-even point is somewhere between 1.5 and 3 times what they think. Contribution margin ratio equals revenue minus all variable costs, divided by revenue. Compute it from a real month, not from a target. 2. Treating Semi-Variable Costs as Fixed The second error hides inside the first. Some costs are neither fixed nor cleanly variable, and the biggest one is usually payroll. A shop with four technicians whose hours track job volume does not have fixed labor. It has stepped labor: flat within a range, then jumping when volume requires another person. Salaried staff who work overtime at peak behave the same way. Treating stepped labor as fixed makes the break-even number look stable right up to the point where volume rises and a new hire appears. Then the business crosses what it thought was break-even and makes less money than it did before, which feels inexplicable and is entirely arithmetic. The practical fix is to model break-even at each capacity step rather than as one number, and to know where your next step is. 3. Leaving Owner Compensation Out of Fixed Costs If the owner takes distributions rather than a salary, owner pay often never appears in fixed costs. The break-even number that results is the point at which the business covers everything except the person running it. Put a market-rate salary for the work the owner actually does into fixed...
