Financial Planning
Break-Even Analysis: Fixed Costs, Variable Costs and Volume
Calculate the sales volume that covers a defined cost base, then test price, unit cost and capacity before trusting the answer.
What you will learn
- classify costs for a defined activity range
- calculate break-even units and sales
- test how price or cost changes move the result
Break-even analysis estimates the volume at which revenue covers a specified cost base. For one product, divide period fixed costs by selling price minus variable cost per unit. The result is only useful when the period, cost boundary, sales mix and capacity assumptions are clear. Operating break-even is not automatically cash break-even.
Choose the unit, period and cost boundary
A unit can be a product, paid service session or completed job. Use one period for fixed costs and sales volume. Separate costs that change with each unit from costs that stay unchanged within the relevant range. A staffing team or machine may add a step cost once capacity is exceeded.
The SBA publishes the single-product break-even formula. Use the unit-economics lesson to inspect the contribution boundary before scaling it into a period calculation.
Work a fictional monthly example
Fictional inputs: selling price is $120 per completed unit, variable cost is $70 per unit and monthly fixed operating costs are $30,000. Every sold unit is delivered, and the fixed-cost base supports the volume being tested.
| Step | Calculation | Result |
|---|---|---|
| Unit contribution | $120 minus $70 | $50 |
| Break-even units | $30,000 / $50 | 600 units |
| Break-even sales | 600 × $120 | $72,000 |
| Variable costs at break-even | 600 × $70 | $42,000 |
| Operating result | $72,000 minus $42,000 minus $30,000 | $0 |
This example excludes financing, tax and investment cash flows. Define treatment of depreciation and other noncash costs with the finance owner; do not label the same calculation both accounting profit and bank cash.
Change one assumption at a time
| Scenario | Price | Unit variable cost | Fixed cost | Break-even units |
|---|---|---|---|---|
| Base | $120 | $70 | $30,000 | 600 |
| Lower selling price | $110 | $70 | $30,000 | 750 |
| Higher unit cost | $120 | $80 | $30,000 | 750 |
| Larger fixed base | $120 | $70 | $36,000 | 720 |
The table identifies which assumption moves the answer. It does not establish that demand exists at that price. If capacity is only 650 units, a 750-unit break-even result cannot be fixed by wishing for more sales; model the capacity change and its costs separately.
Know when the simple formula stops working
- If price equals or falls below variable cost, no finite positive volume covers positive fixed costs under this model.
- Multiple products need a stated sales mix or separate scenarios, not an unweighted average margin.
- Discounts, returns and channel fees can change realized unit contribution.
- A cost step can move break-even just as sales cross the old threshold.
- Stock purchases, payment timing and capital spending can create cash needs before operating break-even.
Copy the break-even worksheet
Decision, period and unit:
Net realized price per unit:
Included variable costs per unit and sources:
Contribution per unit:
Fixed costs for the same period:
Relevant capacity range and next cost step:
Break-even units, rounded up if units are indivisible:
Break-even sales:
Price/cost/volume sensitivities:
Demand evidence and cash-timing exceptions:
Owner and next assumption to verify:Exercise: check the full result
A fictional service sells for $90 per session, incurs $30 variable cost per session and has $18,000 period fixed costs. Find break-even sessions and verify the operating result.
Answer: contribution is $60, so break-even is 300 sessions. Sales of $27,000 less $9,000 variable costs and $18,000 fixed costs equal $0. If only 240 sessions fit the schedule, the practical question is capacity, price or cost structure, not whether 300 is mathematically correct.
Turn the answer into an evidence task
Finish by identifying the least-supported input and who can test it. A quoted supplier price, observed refund cost and signed customer price are different evidence from a planning estimate. Keep assumptions labeled.
Store the approved scenario summary with your fundraising materials in Finta. Give Aurora the inputs and sensitivities to help draft questions for a finance or operating review. Check calculations in the workbook and keep spending and pricing decisions with the accountable team.
Finta Field Guide. By Finta Editorial Team. Sources checked November 14, 2026. Examples are original, fictional teaching exercises, not customer results, benchmarks or individualized financial, accounting, legal or tax advice.