Runway Scenario Calculator
This startup runway calculator models runway with growing revenue: enter cash, burn, revenue and monthly growth to see how many months of cash you have.
What it does
The Runway Scenario Calculator estimates how many months a business can operate before it runs out of cash, while accounting for revenue that grows month over month. It turns a cash balance, a burn rate and a revenue growth assumption into a clear runway in months and years.
Data sources & parameters
This calculator uses standard financial formulas and runs entirely in your browser. It needs no external rate data — your result is computed only from the values you enter above.
We always strive to use the latest data for every variable so our results and reports are as accurate as possible. Even so, errors are possible — you should not rely on this tool or its report alone, and we accept no liability for any decision made based on it.
The formula
For each month: cash = cash − (burn − revenue); revenue = revenue × (1 + growth). Runway = number of months until cash reaches zero or revenue overtakes burn.
How it works
Each month the model subtracts net burn (monthly expenses minus revenue) from the cash balance, then grows revenue by the chosen monthly growth rate. If growing revenue eventually meets or exceeds burn, the business becomes cash-flow positive and the runway is effectively unbounded (capped at 600 months).
Where it is used
- Stress-testing how long startup funding will last
- Seeing how faster revenue growth extends the runway
- Deciding when to raise capital or cut the burn rate
Worked example
A startup holds $500,000.00 in the bank, spends $60,000.00 a month and earns $20,000.00 growing 10% monthly. Because revenue compounds past the burn rate within about a year, the company turns cash-flow positive, giving a runway of … months and a net burn of … in the first month.
What the runway scenario calculator does
The runway scenario calculator shows how long your cash will last and whether growth will arrive before it runs out. Instead of freezing revenue, it grows your income month after month at a rate you set and projects the cash balance forward until either the money is gone or the business turns cash-flow positive.
A company that shows eight months of runway on a static calculation may have far longer, because rising revenue steadily shrinks the amount of cash it loses each month. Seeing that trajectory affects how you plan hiring, spending, and fundraising, and can save you from raising capital in a panic when you did not need to.
How the projection works
The model steps through the future one month at a time. Each month it subtracts your net burn, monthly spending minus current revenue, from the cash balance, then raises revenue by your monthly growth rate, so the next month starts with slightly more income and a slightly smaller loss.
The loop repeats until the cash balance falls to zero, in which case the months elapsed are your runway, or revenue meets or exceeds your spending. At that point the business stops burning cash and the runway is reported as effectively unlimited. The display is capped at 600 months, or 50 years, to show that under your assumptions the money never runs out.
Reading the three results
Runway in months is how founders and investors usually discuss survival time. The same runway in years is easier to reason about for longer-term planning and board conversations.
Net burn in the first month, before any growth, shows where you stand today. A large positive number means cash is leaving quickly now; a negative number means you are already earning more than you spend. Comparing it with the projected runway shows how much of your survival depends on growth materialising.
Why modelling growth matters
Static runway maths can badly mislead for any business with momentum. Ten percent monthly growth sounds modest, yet it roughly triples revenue within a year, so a revenue line that starts well below your burn can overtake it faster than a straight-line estimate suggests.
The reverse also holds: if your growth assumption is too optimistic, the runway will still end even with the growth applied. Modelling the trajectory makes you test whether growth will arrive in time.
How to use the calculator
Enter your current cash balance, including every cash equivalent you can access. Enter your monthly burn: total spending on salaries, rent, software, marketing, and every other outflow. Enter your current monthly revenue, or zero if you are pre-revenue, and the monthly revenue growth rate you believe you can sustain.
Lower the growth rate to see how fragile your plan is if sales slow. Cut the burn by ten percent and watch the runway extend. Add the revenue you expect from a new contract and see whether it makes you cash-flow positive.
Extending your runway
Reducing burn works immediately and is largely within your control: trimming non-essential costs, slowing hiring, and delaying big purchases all cut the monthly loss. Faster revenue growth works from the other side, and because it compounds it can have the largest effect if it is real. Raising cash, usually through fundraising, buys time but is slower and less certain.
Keep enough runway that you never have to raise or pivot in a crisis, and update the model every month as actual figures come in. If growth undershoots your assumption two months running, act before the runway shortens further.
Reading the results
The output is only as good as the growth rate you enter, and real businesses rarely grow in a smooth line. Run a conservative case where growth stalls, a base case matching your recent trend, and an optimistic one; reality usually lands between them. Together they show how long your cash lasts today and how much room you have to be wrong.
This article is general information only and is not financial or business advice.
About This Startup Runway Calculator
Use this startup runway calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.
Frequently asked questions
How is this different from a basic burn rate calculator?
What does an unlimited or capped runway mean?
What is net burn in the first month?
What monthly growth rate should I use?
Does the calculator work in any currency?
Is my data kept private?
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