How it works
Contribution per job = price − cost per job
Break-even jobs = monthly fixed costs ÷ contribution per job, rounded up
Jobs to also pay you = (fixed costs + your pay) ÷ contribution per job, rounded up
Each job first pays for itself. Whatever is left, the contribution, goes toward the fixed bills. Once enough jobs have chipped in to cover them, every extra job is profit.
A worked example
A mobile detailer charges $150 a car. Supplies, fuel and card fees run $45 a car, so each job contributes $105. Fixed costs (insurance, phone, software, the van payment) are $2,000 a month.
$2,000 ÷ $105 = 19.05, so 20 cars a month covers the bills ($3,000 in sales). To also pay herself $3,000 a month: $5,000 ÷ $105 = 47.6, so 48 cars, about 11 a week, or $7,200 in sales.
Common mistakes
- Dividing fixed costs by the price instead of by the contribution. That understates the jobs you need.
- Leaving your own pay out. A business that only breaks even is paying you nothing.
- Counting a helper's wages as fixed when they only work when there's a job (or the reverse). Put each cost where it really behaves.
What this doesn’t tell you
Break-even is a planning threshold, not a forecast of what you'll sell. It assumes an average price and cost, ignores the timing of cash (customers who pay late, a big bill due next month) and leaves out income tax. Seasonal businesses should run it for a slow month and a busy month.
Related calculators
Go deeper: 15 Numbers Every Small Business Owner Should Know, from The Groundwork Review.
Anticipated Questions
What's the difference between fixed and variable costs?
Fixed costs stay the same whether you do one job or fifty: rent, insurance, software. Variable costs rise with every job: supplies, fuel, a helper paid by the job. Some costs are mixed; split them as best you can.
Why round up?
You can't do 19.05 jobs. The 20th job is the one that tips you over.
My break-even is more jobs than I can do. Now what?
That's the most useful answer this calculator gives. The fix is one of three levers: raise your price, cut the cost per job, or cut fixed costs. Raising price usually moves the number fastest; see the price increase calculator.
Does this work for a product business?
Yes. Use units instead of jobs: price per unit, cost per unit, and your monthly fixed costs.
Sources
Last reviewed October 19, 2026. How our calculators work. General information for planning, not legal, tax or financial advice. Found an error? Email info@groundworkbusinessadvisory.com.
