Free tool
Runway Calculator
How many months of runway do you have? Cash divided by net burn gives you the answer. Model new hires to see how each engineer compresses the timeline. URL-shareable so you can send the exact scenario to your co-founder or board.
Frequently asked questions
How is runway calculated?▾
Runway in months = cash on hand divided by net monthly burn. Net burn = gross burn minus monthly revenue. If revenue covers burn (net burn is zero or negative), runway is effectively infinite, the company is cashflow-positive.
When should I start fundraising?▾
Conventional wisdom: start raising at 12 months of runway and close by 6 months. Below 6 months, you are negotiating from weakness. The calculator's danger band reflects this rule of thumb.
How is the per-engineer cost computed?▾
Per-engineer monthly cost = base salary × 1.3 / 12. The 1.3 multiplier covers employer-side payroll taxes (FICA, FUTA, state), healthcare, equipment, and tools. If your loaded cost differs (e.g., remote-only with no benefits ≈ 1.15, or NYC office with full benefits ≈ 1.4), adjust the salary input upward or downward.
Does this account for new revenue from those hires?▾
No, this is a strict cost-side model. New engineering hires usually take 6 to 18 months to contribute revenue, and attributing future revenue to specific headcount is notoriously hard. The conservative move is to model their cost without their revenue contribution and treat any revenue uplift as upside.
What about one-off expenses or seasonal burn?▾
The calculator uses a steady-state monthly burn. If you have lumpy expenses (annual SaaS renewals, end-of-quarter marketing pushes, contractor invoices), either average them into the monthly burn or use this calculator as a baseline and adjust for known events separately.
Can I share my calculation?▾
Yes, every input is encoded in the URL. The 'Copy share link' button copies the current URL to your clipboard. Send it to your co-founder, board, or investor and they open the calculator with the same numbers.
Definition
What is runway?
The canonical definition with cross-references to burn rate and fundraise-timing conventions.
Definition
What is burn rate?
Gross vs net burn, what it means, and why investors care.
Companion tool
SAFE Calculator →
Once your runway tells you it's time to raise, the SAFE calculator tells you what the SAFE will convert to at the next priced round.
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