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The free startup runway calculator.
Know your runway in 30 seconds. Three numbers tell you how long your cash lasts: what's in the bank, what comes in each month, and what goes out. Enter them below, and we'll show your runway, your cash-out date, and a month-by-month forecast you can download.
The 3 numbers you need
Total across every bank + treasury account, today.
Cash you actually collect per month (not MRR/bookings). Use a 3-month average.
Everything leaving the account: payroll, contractors, rent, SaaS, compute.
Make it more accurate (optional)
How fast collected revenue grows month over month.
Planned headcount / spend increase per month.
Cash-flow forecast
| Month | Start | In | Out | End |
|---|
Enter your cash, monthly revenue, and spend to see your runway and forecast.
Want this emailed to you?
We'll send your numbers so you have them on file. Want week-by-week detail? Try the 13-week cash-flow forecast →. Totally optional.
Estimates only, for planning. Not financial, tax, or investment advice.
What is startup runway?
Runway is the number of months your company can keep operating before it runs out of cash, at your current burn rate. For a venture-backed startup it's the clock between fundraises, the single number that tells you how long you have to hit the milestones your next round depends on.
How runway is calculated
The formula is simple:
Runway (months) = cash on hand ÷ net monthly burn
where net monthly burn = monthly cash out − monthly cash in.
The reason we use net burn rather than gross spend is that the revenue you collect each month offsets what's going out, so it stretches how long your cash lasts. This calculator does the math and projects it forward month by month, with optional revenue and expense growth so the curve isn't flat.
Worked example
A startup with $500,000 in the bank, $120,000 of monthly spend, and $20,000 of monthly revenue is burning $100,000 net per month. That's 5 months of runway, with the account hitting zero around month five. Add 10% monthly revenue growth and the runway extends, because each month a little more cash comes in to offset the burn.
How to read your result
- Under 6 months: danger zone. Fundraising itself takes roughly 6 months, so start now or cut burn.
- 6 to 12 months: begin your raise. Line up the round before you're under six months.
- 12 to 18 months: healthy. Focus on the milestones that de-risk the next round.
- 18 months or more: strong position. You're raising from a place of leverage, not need.
- Cash-flow positive: revenue exceeds spend, so you're "default alive" with effectively unlimited runway.
Want the week-by-week view?
Runway answers the big-picture question: roughly how many months you have. When timing matters (lumpy payroll, a quarterly tax payment, a large receipt landing on a specific date), use the 13-week cash flow forecast to catch a short-term cash gap a monthly average can hide.
Runway calculator FAQ
Common questions on runway, burn, and how to read the numbers.
How is startup runway calculated?
Runway is your cash on hand divided by your net monthly burn, where net burn is monthly cash out minus monthly cash in. Example: $500,000 in the bank, $120,000 of monthly spend, and $20,000 of monthly revenue gives $100,000 net burn and 5 months of runway. This calculator does that math and projects it forward month by month, including optional revenue and expense growth.
What is a healthy runway for a startup?
Most venture-backed startups aim to keep at least 12 to 18 months of runway, and to raise with 18 to 24 months after a round closes. Under 6 months is a danger zone: fundraising itself typically takes about 6 months, so you want to start well before then. Cash-flow-positive companies (revenue above spend) are "default alive" and have effectively unlimited runway.
What's the difference between gross burn and net burn?
Gross burn is your total monthly cash outflow, everything leaving the account. Net burn subtracts the cash you collect each month: net burn = cash out − cash in. Runway is based on net burn, because incoming revenue extends how long your cash lasts. This tool asks for both so it can show your true net burn.
How often should I update my runway?
Recalculate every month after your books close, and any time a major input changes: a new hire, a price change, a closed round, or a big one-time cost. Runway is only as accurate as the cash-in and cash-out numbers behind it, so a current monthly close matters.
When should I use the 13-week cash flow forecast instead?
Use this runway calculator for the big-picture question: roughly how many months of cash you have. Use the 13-week cash flow forecast when timing matters week to week: lumpy payroll, a quarterly tax payment, or a large receipt landing on a specific date. The weekly view catches a short-term cash gap that a monthly average can hide.