Break-Even Calculator
How many units you must sell to cover fixed costs.
Your figures
Result
How to use this tool
- Enter your own figures over the defaults — Fixed costs, Price per unit, Variable cost per unit.
- The answer updates as you type. There is no button, and nothing is sent anywhere.
- Change Fixed costs on its own to see how much it moves the result — the worked example below shows exactly that.
The key figure is contribution margin — price minus variable cost. It is what each sale actually contributes toward fixed costs, and small price changes move it disproportionately.
How it works
This takes 3 inputs — fixed costs, price per unit, variable cost per unit — and returns break-even units, break-even revenue, contribution margin per unit and margin ratio. The whole calculation happens in this page as you type: there is no submit button, no request, and nothing stored.
Because it recalculates on every keystroke you can use it as a sensitivity test rather than a one-shot answer. Moving fixed costs alone from 20,000 to 22,000 changes break-even units from 1,000 to 1,100 — the worked example below sets that out in full.
A worked example
Worked through with the figures the page already has in it: fixed costs of 20,000 and price per unit of 50, and the rest as shown, giving break-even units of 1,000. These numbers come from running the calculator’s own code, not from being typed in here, so they cannot drift away from what you see on screen.
Starting from:
- Fixed costs: 20,000
- Price per unit: 50
- Variable cost per unit: 30
| Result | Value |
|---|---|
| Break-even units | 1,000 |
| Break-even revenue | 50,000.00 |
| Contribution margin per unit | 20.00 |
| Margin ratio | 40.0% |
What happens when one input moves
Holding everything else steady and changing Fixed costs from 20,000 to 22,000 — 10% — moves the answer like this:
| Figure | 20,000 | 22,000 |
|---|---|---|
| Break-even units | 1,000 | 1,100 |
| Break-even revenue | 50,000.00 | 55,000.00 |
| Contribution margin per unit | 20.00 | 20.00 |
| Margin ratio | 40.0% | 40.0% |
That is usually the number worth arguing over: it is easier to move than the headline amount, and the difference compounds across the whole term.
Break-Even Calculator — frequently asked questions
What counts as a fixed cost?
Costs that do not change with volume: rent, salaries, insurance, software subscriptions. Variable costs scale with each unit — materials, packaging, payment processing, shipping.
Why does a small price rise help so much?
It goes entirely to contribution margin. If your margin is $20 and you raise price by $2, margin rises 10% and break-even volume falls by roughly 9%.
What if variable cost exceeds price?
You lose money on every sale and volume makes it worse. That has to be fixed before anything else.
Is this calculator free?
Yes, with no account, no limits and no data collection. It runs entirely in your browser.
Should I rely on this for a financial or medical decision?
No. It is a planning estimate built on standard formulas and stated assumptions. For decisions that matter, speak to a qualified professional who can account for your full circumstances.
How accurate is the Break-Even figure?
The arithmetic is exact. With the defaults on this page — fixed costs 20000, price per unit 50, variable cost per unit 30 — it returns break-even units of 1,000. What limits accuracy is the assumptions, not the maths: change fixed costs to 22000 and the same formula gives 1,100. Treat it as a well-founded estimate, not a quotation.
Related tools
From other categories
Background reading: Loan, Mortgage and Investment Calculators Explained
Nothing is sent anywhere. The figures you type stay in this page and are never transmitted or stored — how that works.
Disclaimer. The formula is exact; the answer is only as good as the figures and assumptions above. Not financial, tax, medical or legal advice. Full disclaimer.