Startup Runway Calculator
Estimate how many months of cash your startup has left based on your burn rate — with scenario analysis for revenue and cost changes, and a cash-over-time chart.
Written by the CalcBundle Research & Editorial Team · Reviewed by the Quality Review Team · Transparent formulas · results are estimates, not advice. · Updated
Startup runway
Enter your current cash and monthly expenses to estimate runway.
What is a startup runway calculator?
Runway is the single number founders watch most closely: how long until the money runs out. This calculator turns your cash balance, revenue and monthly expenses into a runway in months, an estimated cash-out date, and a chart of your cash balance over time.
How runway is calculated
- Net burn = Monthly cash outflow − Monthly revenue
- Runway (months) = Current cash ÷ Net monthly burn
If revenue meets or exceeds expenses, there is no finite runway — the calculator says you are cash-flow positive rather than showing an infinite number.
Scenario analysis
Runway is highly sensitive to small changes. The scenario table shows how your runway shifts with +10%/+20% revenue or −10%/−20% expenses, so you can see which lever buys you the most time before you need to raise or cut costs.
Worked example
With $500,000 in the bank and a net burn of $50,000 a month, you have $500,000 ÷ $50,000 = 10 months of runway. Now pull the two levers. Cutting expenses 20%, to a $40,000 net burn, extends runway to 12.5 months — a 25% gain from a 20% cut, because runway responds disproportionately when burn is the denominator. Lifting revenue instead has the same kind of effect: an extra $10,000 a month of revenue also drops net burn to $40,000. Seeing both paths side by side helps you choose the one that is realistic for your business right now.
Why runway is the founder's master metric
Runway ties almost every other number together — burn, revenue, hiring plans and fundraising timing all ultimately express themselves as months of cash remaining. It is the metric that converts strategy into a deadline: every goal on the roadmap has to be achievable within the runway, or the plan needs to change. Managing runway well is less about a single calculation and more about a habit — checking it regularly, protecting a healthy buffer, and treating the months you have as the scarce, decision-shaping resource they really are.
Runway, burn and cash flow
Runway is driven by burn rate. To model the timing of cash in and out in detail, use the cash flow calculator, and if you are considering debt, the business loan calculator shows the repayment impact.
Frequently asked questions
What is startup runway?
Runway is how many months your startup can keep operating before it runs out of cash, given your current cash balance and net monthly burn.
How is runway calculated?
Runway = current cash ÷ net monthly burn, where net burn = monthly cash outflow − monthly revenue. For example, $500,000 cash and $50,000 net burn gives 10 months of runway.
What is burn rate?
Burn rate is how much cash you spend each month. Gross burn is total spend; net burn subtracts revenue. Net burn is what determines runway. See the dedicated burn rate calculator for more.
How can founders extend runway?
Increase revenue, reduce expenses, raise capital, or improve collections. The scenario table shows how a 10–20% change in revenue or costs shifts your runway.
How much runway should a startup keep?
A common guideline is to maintain at least 12 to 18 months of runway, and to start raising the next round when you have roughly six to nine months left, because fundraising takes time and negotiating from a near-empty account weakens your position. The right buffer depends on how predictable your cash flow is and how long raises take in your market. The core principle is to never let runway shrink to the point where you are forced to accept bad terms or make panicked cuts.
What happens as a startup approaches the end of its runway?
Options narrow and get more expensive the longer you wait, which is why runway should be managed well before it becomes critical. With ample runway you can raise on good terms, cut costs deliberately, or pivot with room to experiment. With only a couple of months left, you may face a down round, emergency layoffs, or a forced sale. The lesson is that runway is a decision-making resource: the more of it you have, the more good choices remain open to you.
Does runway assume burn stays constant?
The basic runway formula assumes your net burn holds steady, which is a simplification. In reality burn changes as you hire, as revenue grows, or as you cut costs, so runway is a snapshot based on current conditions rather than a fixed prediction. That is exactly why the scenario view is useful — it shows how runway shifts under different revenue and cost assumptions, giving you a range rather than a single, potentially misleading number.
Related calculators
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Calculate gross and net monthly burn, annualized burn and runway.
Cash Flow
Project net cash flow and your ending cash balance from inflows and outflows.
Business Profit
Turn revenue and expenses into gross, operating and net profit with clear margins and a visual breakdown.
Business Loan
Work out loan payments, total interest and a full amortization schedule.
Disclaimer. This calculator provides estimates for informational purposes only. Results are based on the information you enter and the assumptions used by the calculator. Actual financial, tax, business valuation, lending, marketplace or investment outcomes may differ. Consider consulting a qualified professional for decisions involving significant amounts of money. Runway is an estimate based on the figures you enter. Actual cash flow varies month to month.