Runway Calculator
Divide your cash balance by net monthly burn to see how many months of runway remain — and model how fast that number shrinks if burn keeps growing.
Reviewed by the CalcCafe editorial team · Last updated 18 July 2026 · How we test our tools
Example
With $900,000 in the bank and a net burn of $75,000 per month, runway = 900,000 ÷ 75,000 = 12 months, or 1.0 years — cash out roughly one year from today. Note the sensitivity: if burn grows just 5% a month from that starting point, the same cash covers only 9 full months, and under the 6-9 month fundraising rule you would need to start raising almost immediately.
How it works
With constant burn, runway (months) = cash balance ÷ net monthly burn, and years = months ÷ 12. If you set a monthly burn growth rate, the tool simulates month by month — deducting the current burn, then growing it by the set percentage — and counts how many full months your cash covers (capped at 240 months). Net burn means outflows minus revenue; if revenue is growing, your effective burn growth can be negative and real runway will beat the simple division.
Good to know
The standard post-raise target is 18-24 months of runway. That is long enough to hit the milestones that justify the next round — meaningful revenue growth, retention proof, a repeatable sales motion — plus the 6+ months the next fundraise itself consumes. Rounds sized to 12 months leave almost no room for a missed quarter, and in tighter funding markets many investors now advocate stretching toward 24-30 months at the cost of slower hiring.
Runway shrinks faster than linear whenever burn is growing. $900k at a flat $75k/month lasts 12 months, but let burn grow 5% monthly — one steady hiring cadence — and it covers only 9 full months. The intuition founders miss is that the naive cash÷burn figure is only valid at the instant you compute it; if headcount plans, salary raises and infrastructure costs are trending up, your true runway is always shorter than the division suggests. Model the growth case, not just the snapshot.
Start fundraising with 6-9 months of runway left, not less. A competitive process takes 3-6 months from first deck to money in the bank, and term-sheet leverage collapses when investors can see you are weeks from a missed payroll — everyone can read a runway chart. Counting backwards: on an 18-month runway, you have roughly 9-12 months of heads-down execution before the next raise effectively begins. Plan milestones accordingly.
If runway is short, you have exactly two levers: cut net burn or grow revenue. Cuts act immediately and certainly — a $25k/month reduction on $75k burn stretches $900k from 12 to 18 months — while revenue growth acts slowly and probabilistically, since new MRR takes months to compound into material burn relief. The default-alive question is the discipline: at current growth, do you reach breakeven before zero? If not, cut early and once, deeply enough that you do not have to cut again.
Frequently asked questions
How much runway should a startup have after raising?
The standard target is 18-24 months. That funds the milestones the next round will be judged on, plus the 3-6 months a fundraise takes. In tighter markets many investors recommend stretching toward 24-30 months by moderating hiring plans.
When should I start fundraising?
With 6-9 months of cash remaining, at the latest. A well-run process takes 3-6 months end to end, and your negotiating leverage drops sharply once investors can see you are nearly out of money.
Why is my real runway shorter than cash divided by burn?
Because that division assumes burn never changes. Planned hires, salary increases, annual contract renewals and rising infrastructure costs all grow burn over time, so cash runs out sooner than the snapshot suggests. Use the burn-growth input to model it.
Is my data uploaded anywhere?
No — this calculator runs entirely in your browser. Your cash and burn figures never leave your device, and the page works offline once loaded.
People also ask
How do I calculate my startup's runway?
Divide your current cash balance by your net monthly burn (outflows minus revenue). $900,000 in the bank with $75,000 monthly net burn gives 12 months of runway. If burn is growing, simulate month by month instead — the answer will be shorter.
What is a good runway for a seed-stage startup?
18-24 months post-raise is the widely used benchmark: enough to reach Series A milestones and still leave 6+ months for the raise itself. Less than 12 months of runway generally means fundraising or cost cuts should start now.
Does revenue count when calculating runway?
Yes — runway should be computed on net burn, which is spending minus revenue collected. Growing revenue effectively shrinks net burn each month, so a company with flat costs and rising revenue has more real runway than the simple division shows.
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Sources & references
These tools follow our methodology and provide educational estimates only — verify important figures with a qualified professional.