Burn Rate & Runway Calculator
Divide your cash by your monthly burn to see how many months you have before the tank is empty — and when to start raising. Free and private — nothing leaves your browser.
Burn Rate & Runway
When do we run out of money?
How it works
Runway (months) = Cash in Bank / Net Monthly BurnNet burn is what actually leaves the company each month: operating costs minus any revenue coming in. Divide cash by that number and you get the survival timeline — the single number investors ask about first. The subtlety is that burn is rarely constant: hiring plans, annual contracts, and growth spend all bend the curve, so a straight-line runway is usually the optimistic case. Treat the output as a ceiling, not a promise.
Worked example
With €900,000 in the bank and €75,000 net monthly burn, runway is 12 months. Since a fundraise realistically takes 3-6 months from first deck to money in the bank, the raise needs to start around month 6 — not month 10. If two new hires push burn to €90,000, runway drops to 10 months and the margin for a slow round nearly disappears. This is why the standard advice is to raise 18-24 months of runway, not 12.
Frequently asked questions
What is the difference between gross and net burn?→
Gross burn is total monthly operating spend; net burn subtracts revenue. A company spending €100k and earning €40k has €100k gross burn but €60k net burn. Runway is computed on net burn — revenue extends your life.
How much runway should a startup keep?→
The common rule is to raise 18-24 months and to start the next raise with at least 6 months still in the bank. Rounds routinely take 3-6 months, and negotiating leverage evaporates when the cash-out date is visible on the horizon.
How can I extend runway?→
Three levers: cut burn (headcount is usually the biggest line), grow revenue (each euro of new MRR extends the timeline), or add capital (equity, venture debt, or revenue-based financing). Cuts act immediately; revenue compounds; raising takes months — plan in that order.
No black boxes — the exact formula is shown above · Last reviewed July 2026