Know how much you must sell before you make a profit
A small studio may bring in $8,000 in a busy month and still struggle to pay rent, software, insurance, and contractors. Revenue alone does not tell the owner whether the business is profitable. A break-even calculation estimates the sales volume at which revenue covers the costs included in the model. Every sale beyond that point contributes toward profit, while sales below it leave a gap to fund.
The US Small Business Administration describes the same basic unit formula: fixed costs divided by price per unit minus variable cost per unit. See the SBA break-even point guide for its definition and limitations.
Classify costs before opening a spreadsheet
Fixed costs stay broadly the same across a normal range of sales for the period being measured. Examples include rent, base software subscriptions, insurance, and fixed salaries. Variable costs change with each unit, project, or transaction: materials, packaging, payment processing, per-order shipping, or subcontractor time that scales with the work. Some costs are mixed, such as a phone plan with a fixed monthly charge and usage fees.
Use a consistent time period. If rent is monthly, monthly revenue and monthly costs should be used in the same calculation. For annual insurance, convert it to a monthly allocation for planning instead of forgetting the bill for eleven months and acting shocked when it arrives.
The break-even formulas
Contribution per sale = selling price per sale − variable cost per sale.
Break-even units = fixed costs ÷ contribution per sale.
Contribution-margin ratio = contribution per sale ÷ selling price.
Break-even sales revenue = fixed costs ÷ contribution-margin ratio.
For unit calculations, round up to the next whole sale. Thirty-one point four projects are not a valid operating plan.
Worked example: a service business
Suppose a small design business has $2,400 in monthly fixed costs. Each project sells for $120, and the variable costs directly associated with a project are $45. Contribution per project is $75. Dividing $2,400 by $75 gives 32 projects, so the modeled break-even target is 32 projects per month. The contribution-margin ratio is $75 ÷ $120 = 62.5%. The corresponding revenue break-even is $2,400 ÷ 0.625 = $3,840.
| Input | Example |
|---|---|
| Monthly fixed costs | $2,400 |
| Price per project | $120 |
| Variable cost per project | $45 |
| Contribution per project | $75 |
| Break-even project count | 32 |
| Break-even revenue | $3,840 |
Stress-test the estimate
Recalculate at a lower selling price, a higher materials cost, and a slower month. A 10% planning cushion can help account for small costs that are easy to miss, but it is not a replacement for listing expenses honestly. Check whether the model includes owner labor, refunds, payment fees, taxes, debt service, and equipment replacement. Whether each item belongs in the break-even formula depends on the decision the calculation is meant to support.
Common break-even mistakes
- Counting gross receipts as profit without deducting variable costs.
- Mixing annual fixed costs with monthly sales.
- Using an average price while ignoring products with very different margins.
- Forgetting owner labor and then calling unpaid work a healthy profit.
- Treating a break-even estimate as a guarantee instead of a scenario to update.
Put related calculations together
- Percentage Calculator for contribution-margin ratios and price changes.
- Freelance Rate and Project Quote Calculator to test whether a service price covers billable time.
- Invoice Maker to document the sales that actually come in.
Turn the result into an operating target
Break-even is the floor, not a growth goal. Set a sales target above it, check actual numbers monthly, and update cost assumptions after supplier increases, a new software subscription, or a price change. A calculation that is revisited regularly gives an owner useful early warning; a spreadsheet made once and forgotten is just decoration with cells.
Note: This article is general educational information, not individualized tax, investment, legal, or financial advice. Verify current rules and your own numbers before making a decision.