Burn Rate & Runway Calculator
Work out gross burn, net burn and how many months of runway your cash covers, plus the month it would run out.
Cash position
Runway
Months of runway at the current net burn
Enter your numbers to see your runway.
Eighteen months of runway is a common safety floor
A widely used rule in venture-backed startups is to keep at least 18 months of runway. Below 12 months, you are fundraising under pressure and often accepting worse terms. Below 6 months, the options narrow to bridge rounds and hard conversations. Because burn changes quickly, track runway every week rather than once a month.
Gross burn vs net burn
- Gross burn is everything you spend in a month.
- Net burn is spending minus revenue, the amount your cash balance actually drops each month.
- Runway is cash in the bank divided by net burn.
The calculator assumes revenue and expenses stay flat. If revenue is growing, your real runway is longer. If you are about to hire, it will be shorter, so rerun the numbers with your planned costs.
Frequently asked questions
Should I include investments and capex?
For burn rate, focus on operating cash flow. Track capital expenses separately as part of your total cash plan, since they are often one-off.
What if my revenue is seasonal?
Use an average of the last three to six months for revenue and expenses. A single strong or weak month can make runway look far better or worse than it is.