Burn Rate & Runway Calculator
Burn rate and runway are the vital signs of any venture-backed startup, because they answer the most existential question a founder faces: how long until we run out of money? Gross burn is your total monthly cash outflow, while net burn subtracts any revenue you bring in — it is the real rate at which your bank balance shrinks. Dividing your current cash by net burn gives your runway, the number of months you can operate before the account hits zero. Runway dictates everything: how aggressively you can hire, when you must start fundraising (typically with six-plus months to spare), and how much risk you can absorb. Enter your cash, revenue, and expenses to see your burn and runway, and know exactly how much time you have.
Your Numbers
Results
Results update live as you type. Estimates only — not financial, tax, or investment advice.
The Formula
Net Burn = Monthly Expenses − Monthly Revenue; Runway = Cash Balance ÷ Net Burn
Understanding the Burn Rate & Runway Calculator
The distinction between gross and net burn matters enormously as you scale. Early on, with little revenue, the two are nearly identical. As revenue grows, net burn can fall well below gross burn, extending runway even as headcount rises. A company can even reach 'default alive' — the point where growing revenue will cover expenses before the cash runs out — which fundamentally changes its fundraising leverage and survival odds.
Runway is a fundraising clock as much as a cash figure. Because raising a round typically takes three to six months, experienced founders begin fundraising with at least six to nine months of runway remaining, never waiting until the tank is nearly empty when they have no leverage and few options. Watch the trend, not just the snapshot: a burn rate that climbs faster than revenue is a warning to tighten spending or accelerate the raise before runway becomes critical.
Frequently Asked Questions
What's the difference between gross and net burn?
Gross burn is your total monthly cash outflow — all expenses combined. Net burn subtracts the revenue you collect, showing the actual rate your cash balance declines. Net burn is the number that determines runway, because incoming revenue genuinely offsets what you spend each month.
How much runway should a startup have?
A common rule is to maintain at least 6 months of runway at all times and to start fundraising when you have 6–9 months left, since raising a round takes months. Post-raise, many startups target 18–24 months of runway to reach the next meaningful milestone with a buffer.
What does it mean to be 'default alive'?
A startup is 'default alive' if, on its current growth and spending trajectory, revenue will cover expenses before its cash runs out — meaning it can survive without raising more money. 'Default dead' is the opposite. Knowing which you are should drive every spending and fundraising decision.