Free calculator · Venture & Startup Finance
Runway & Default Alive / Default Dead
Projects whether a startup reaches profitability before its cash runs out, the default alive or default dead question, along with current and worst-case runway. Inputs are cash on hand, monthly gross burn, current monthly revenue, and the monthly revenue growth rate.
By Devon Coombs, CPA, MBA · Teaching Professor of Finance, Santa Clara University · Reviewed August 2026
From the author: Devon Coombs, CPA, MBA teaches finance at Santa Clara University and works with corporate teams on practical AI.
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Runway & Default Alive / Default Dead
Paul Graham diagnostic
Default Alive
Reaches profitability in ~10 months, before cash runs out.
Net burn / mo
$120,000
spend − revenue
Current runway
10.0 mo
cash ÷ net burn
Worst-case runway
6.0 mo
cash ÷ gross burn (rev → 0)
Healthy window
12–18 mo
raising a round takes 3–6 mo
The fatal pinch is short runway, slow growth, and locked-in costs at once. Recalculate default alive/dead monthly and keep a 15–18 month buffer so committed costs never trap you.
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This calculator comes from the free Entrepreneurial Finance course, where the concept is taught with readings, worked examples, and practice questions.
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Built by Devon Coombs, CPA, MBA, Teaching Professor of Finance at Santa Clara University.