Break-Even Calculator
Where does this product, line, or business stop losing money? Break-even units, contribution margin, and margin of safety — with a chart that shows the curve, not just a number.
per unit
of price
Solid green = profit at each volume level. Dashed blue = revenue. Dashed gray = total costs (fixed + variable). The break-even point is where profit crosses zero.
View the TypeScript implementation on GitHub: packages/calc/src/break-even.ts · view tests
What this means
Break-even is the floor — the volume at which a product, line, or business stops bleeding money. It's deliberately a low bar; the business goal isn't to break even, it's to clear break-even with enough margin of safety that a 20% drop in volume doesn't push you back underwater. The most useful question this calculator answers isn't "where is break-even?" — it's "how much room do I have between my actual sales and break-even, and how does that room change if I lose a customer or input costs rise?"
The two highest-leverage levers in this math are price and variable cost — both move the contribution margin directly, which is the denominator of the break-even formula. A 10% price increase with constant variable cost lowers break-even units by more than 10% (the leverage compounds). The lowest-leverage lever is fixed-cost reduction — it lowers break-even proportionally but doesn't change the underlying unit economics. If your unit economics are broken (CM < 0 or barely positive), no amount of cost-cutting on rent or salaries fixes the business; you need pricing or product change.
Worked example
SaaS product priced at $100/month with $40 of monthly variable cost per customer (payment processing, transactional email, per-seat cloud cost). Fixed costs of $60,000/month (engineering salaries, rent, software). Contribution margin per customer is $60, CM ratio is 60%. Break-even is 1,000 customers / $100,000 MRR. If the company is currently at 1,500 customers, margin of safety is 33% — adequate but not generous; a 33% drop in customers (e.g. churn spike during a recession) puts the company back at break-even. Operating profit at 1,500 customers: 1,500 × $60 − $60,000 = $30,000/month. A $10 price increase to $110 (and customers stay) raises CM to $70 and drops break-even to ~857 customers — same revenue base now produces $45K/month of profit. The price lever beats the cost lever on operating leverage, almost every time.
Frequently asked questions
The information and tools on this website are for general educational purposes only and do not constitute financial, investment, legal, or tax advice. Consult a licensed professional for decisions specific to your situation.