Free toolsRunway Calculator
How many months until zero — and what moves the date
Runway is the only startup metric that can kill you. This calculator takes your cash on hand, monthly spend, and current revenue — plus a growth assumption — and shows the month you run out, how default-alive or default-dead you are, and how much a cut in burn actually buys you.
10 months of runway
You hit zero around June 2027 — growth buys you 2 extra months vs. flat revenue.
Rule of thumb: cutting burn by 20% (to $6,400/mo) stretches this to 15 months. Raising revenue growth to 10%/mo gets you 13 months.
Common questions
- How is startup runway calculated?
- The simple version is cash ÷ net burn (monthly spend minus monthly revenue). This calculator goes one step further: it compounds your revenue growth month by month, so if revenue is growing, your real runway is longer than the flat math suggests — and if growth is fast enough, you become "default alive" and never hit zero.
- What does default alive mean?
- A term from Paul Graham: a startup is default alive if, on its current trajectory, revenue covers expenses before the money runs out — no new funding required. Default dead means the opposite, and the honest question becomes what changes the trajectory: cutting burn, raising prices, or raising money.
- What counts as monthly burn?
- Everything that leaves the bank account in a normal month: salaries and contractors, software, hosting, rent, ads, fees. Use a real average from the last 2–3 months rather than a hopeful budget — runway math is only useful when the inputs are honest.
- How much runway should a startup have?
- Conventional wisdom says raise or maintain 12–18 months, because meaningful product and revenue milestones rarely happen in less. Under 6 months means the fundraise-or-cut decision is already overdue — you need time for whatever you try to actually work.
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