Break-Even Calculator (Units)
Units sold so contribution margin covers fixed overhead for that horizon.
Open calculator →Startup Runway Calculator
Months of runway from cash divided by estimated monthly burn when burn holds steady.
Overview
Use in planning meetings—not as a covenant test. Spike hiring, prepaid revenue, fundraising, or lumpy payroll taxes will shred a flat-burn assumption overnight.
When to use this calculator
- Before you hire, sign a big lease, or commit to a heavy marketing push
- When burn is uneven and you still need a single months-left number to discuss
- When you update the team on cash after a fundraise or large receivable
- When you want a quick check on whether revenue growth is close to covering burn
Rule of thumb
Months of runway assume burn stays flat. New hires, campaigns, or revenue ramps can shorten or lengthen the truth fast.
Terms used in this calculator
- Conversion rate
- Share of a clear baseline group—visits, sessions, leads—that finished the goal you named.
- CPC
- What you paid on average for one ad click.
- ROI
- Return compared to everything you counted as investment—often wider than ads alone when people say "full ROI."
Calculator
Runway (months)
6.86 mo
Results are simplified estimates for educational purposes only and should not be treated as financial, accounting, legal, or tax advice. See our disclaimer for details.
Formula
Cash balance ÷ monthly burn. Burn should be whatever leadership agrees counts as recurring net cash-out.
Example calculation
Using the default example values from the JSON seed for this tool:
- Cash balance
- 240000
- Monthly burn
- 35000
Result: 6.86 mo (Runway (months))
How to interpret this result
Runway is cash balance ÷ monthly burn if burn stays flat.
It ignores new revenue ramps, fundraising, or one-time cash events unless you change the inputs.
Use ranges when burn is volatile month to month.
Common mistakes
- Treating undrawn credit as cash on hand without intent to use it.
- Ignoring large payables due before the runway horizon ends.
- Assuming flat burn when revenue is ramping materially.
What to do next
Break-even unit math or burn detail worksheets come next if runway feels tight.
How to improve this result
- Model a lower revenue month and a higher burn month side by side—flat inputs lie fastest.
- Pull major payables or payroll tax due dates into the conversation.
- Start investor or debt conversations before the graph hits single-digit months.
Recommended tools
- Baremetrics SaaS metrics and subscription analytics dashboards.
- ChartMogul Subscription analytics for revenue, churn, and cohort reporting.
- ProfitWell Pricing and retention resources for subscription businesses.
FAQ
- Do I include receivables as cash?
- Only if they are realistically collectible within the runway window you care about.
- What about an undrawn credit line?
- Model it deliberately—cash runway and liquidity runway differ.
- Why does runway change month to month?
- Revenue ramps and one-time expenses distort any single snapshot.
- Is runway the same as break-even?
- No—runway watches cash clocks; unit break-even solves contribution margin puzzles.
- Should founders share this number verbatim?
- Treat it as a scenario label; pair with sensitivities verbally.
Related calculators
CAC Calculator
Sales + marketing spend in a slice ÷ newly acquired customers counted the same window.
Open calculator →LTV Calculator (Simple Gross Margin Adjusted)
Simplified annuity-style gross LTV using ARPA, margin, and churn in shared time units.
Open calculator →Affiliate disclosure
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