How break-even analysis works
Break-even analysis answers the question: how many units do I need to sell each month before my business stops losing money? It separates costs into two categories:
- Fixed costs — costs that don't change with sales volume: rent, base payroll, insurance, subscriptions, loan payments, and other overhead. These are the same whether you sell 0 or 1,000 units.
- Variable costs — costs that scale with every unit sold: raw materials, direct labor, packaging, credit card processing fees, and sales commissions.
The key derived number is the contribution margin — how much of each sale is left over after paying variable costs to contribute toward fixed costs and profit:
Contribution margin = selling price − variable cost per unit
Contribution margin rate = contribution margin ÷ selling price
The break-even point in units is:
Break-even units = fixed costs ÷ contribution margin
And in revenue:
Break-even revenue = fixed costs ÷ contribution margin rate
To include a profit target, add the target to the fixed costs before dividing — profit is treated as another fixed requirement the contribution margin must cover:
Target-profit units = (fixed costs + target profit) ÷ contribution margin
Worked examples
Example 1 — coffee shop: A coffee shop has $8,000 in monthly fixed costs (rent, base staff, utilities). Each cup sells for $5.00 and costs $2.00 in materials and direct labor (variable cost). The owner wants to know how many cups they need to sell to break even, and how many to hit a $3,000 monthly profit target.
| Item | Value |
|---|---|
| Selling price | $5.00 |
| Variable cost per cup | $2.00 |
| Contribution margin | $3.00 |
| Contribution margin rate | 60% |
| Monthly fixed costs | $8,000 |
| Break-even units | 2,667 cups ($13,335 revenue) |
| Units for $3,000 profit target | 3,667 cups ($18,335 revenue) |
The shop earns $3.00 of contribution margin per cup. Every cup sold above 2,667 goes directly to profit at $3.00 each.
Example 2 — online course: A consultant sells an online course for $299. Variable costs are essentially zero (hosting and payment processing ≈ $4 per sale). Monthly fixed costs are $1,500 (software, advertising, accountant).
| Item | Value |
|---|---|
| Selling price | $299.00 |
| Variable cost per sale | $4.00 |
| Contribution margin | $295.00 |
| Contribution margin rate | 98.7% |
| Monthly fixed costs | $1,500 |
| Break-even sales | 6 courses ($1,794 revenue) |
High-margin digital products break even very quickly but the challenge is generating consistent sales volume, not reducing unit costs.
Assumptions and limitations
- This calculator assumes a single product or average selling price. If you sell multiple products at different margins, use your blended average selling price and blended average variable cost, or run the analysis separately for each product line.
- Break-even analysis assumes costs are truly fixed or truly variable. In practice, many costs are semi-variable (a supervisor's salary is fixed up to a volume threshold, then steps up). This calculator does not model step-fixed costs.
- The calculator uses a monthly time frame. If your business is seasonal, a month-by-month analysis will give you more useful results than an annual average.
- Break-even is an accounting breakeven — it ignores taxes and the time value of money. Your actual cash position also depends on working capital timing (when customers pay vs. when you pay suppliers).
- Break-even analysis does not tell you whether your price is right or whether you can reach the required volume. Those are market questions; use the result to test assumptions against your market research and capacity.
Frequently asked questions
- What counts as a fixed cost?
- Costs that don't change when you sell one more unit: rent, base salaries (not commission), equipment loan payments, insurance, software subscriptions, accounting fees, and utilities up to a baseline. The test is: "Would I still pay this if I sold nothing this month?" If yes, it's fixed. Owner draws and distributions are also often treated as fixed costs when analyzing a profitable steady state.
- What counts as a variable cost?
- Costs that exist only because you made a sale: raw materials, component parts, direct labor paid per unit, packaging, shipping, credit card processing fees, and sales commissions. If the cost disappears when sales drop to zero, it's variable.
- My contribution margin is negative — what does that mean?
- A negative contribution margin means your variable costs exceed your selling price. You lose money on every unit sold, regardless of volume — selling more makes the loss worse, not better. The only solutions are to raise your price or reduce variable costs to the point where the margin is positive. The calculator returns an error in this case.
- How is break-even different from profitability?
- Break-even means you cover all costs — both fixed and variable — with zero net profit. Profitability requires revenue beyond break-even. The "target profit" input lets you set a specific profit goal and see the sales volume required to reach it. Many lenders and investors look at whether the projected sales are plausibly achievable given the market.
- Can I use this calculator for a service business?
- Yes. For a service business, "unit" is typically one hour billed, one client engagement, or one job. The selling price is your rate per unit; variable cost is your direct cost per unit (subcontractor fees, materials, travel expenses billed at cost). Fixed costs are your monthly overhead regardless of how many clients you serve.
Sources
- Investopedia — "Break-Even Analysis: Definition and How to Calculate and Use It" (accessed 2026-10-04)
- SCORE — "How to Calculate Your Break-Even Point" (accessed 2026-10-04)