Runway is the number that decides almost every startup decision, and it is just one division away. Enter your cash, your monthly revenue and your monthly expenses, and this free calculator works out your gross burn, your net burn, your months of runway, and the date your cash runs out if nothing changes.
Estimates only. Runway assumes your revenue and expenses stay flat at the numbers you entered, with no new funding, no seasonal swings and no one-off costs. Real burn moves month to month, so re-run this whenever your costs or sales change.
Gross burn vs net burn, in plain terms
Gross burn is everything your business spends in a month: payroll, rent, software, ads, everything. Net burn is what is left after revenue: expenses minus revenue. Runway is your cash in the bank divided by net burn. A startup with $60,000 in the bank, $8,000 a month in revenue and $14,000 a month in expenses has a gross burn of $14,000, a net burn of $6,000, and a runway of exactly 10 months. If revenue covers expenses, there is no net burn and no cash-out date — the calculator says so instead of inventing one. Investors usually want to see 12 to 18 months of runway after a raise, which is why this number drives when you fundraise, when you hire, and when you cut.
How to get more runway without raising money
There are only three levers: raise revenue, cut expenses, or add cash. Cutting is fastest — a $1,000 monthly cost cut on the example above stretches runway from 10 months to 12. Growing revenue is slower but compounds, because every new dollar of monthly revenue cuts net burn by a dollar. Adding cash through a raise works, but it dilutes you, and it works best from a position of discipline. That trade-off — growing fast versus lasting long enough for profit to matter — is the subject of our analysis of startups choosing profit over growth.
Frequently asked questions
What is a good runway for a startup? Most founders and investors treat 12 to 18 months as healthy: long enough to hit milestones and raise the next round without desperation, short enough to keep spending honest. Under 6 months is an emergency. How often should I recalculate? Monthly, right after the books close — burn is an average, and one hiring round or one big contract changes it completely. Does runway include future funding? No. Runway counts only cash you actually have. Money you hope to raise is not runway until it is in the bank.