Startup Runway Calculator
How Many Months Until the Cash Runs Out
Runway answers the single most consequential question a startup can ask: at the current rate of spending, how many months remain before the cash balance hits zero? It converts an abstract bank balance into a concrete deadline, which shapes everything from hiring plans to fundraising urgency.
The Formula
Runway (months) = Cash Balance / Net Burn Rate
If monthly revenue meets or exceeds monthly expenses, net burn is zero or negative and runway is effectively infinite — the company is cash-flow positive.
Runway at Different Cash and Burn Levels
| Cash balance | Net monthly burn | Runway |
|---|---|---|
| $50,000 | $5,000 | 10.0 months |
| $100,000 | $8,000 | 12.5 months |
| $250,000 | $20,000 | 12.5 months |
| $500,000 | $45,000 | 11.1 months |
Runway depends on the ratio of cash to burn, not the absolute size of either — a small startup and a well-funded one can have identical runway despite very different bank balances.
Where This Calculation Matters
- Fundraising timing — most investors expect a raise to close with several months of runway still remaining, not at zero.
- Hiring plans — each new hire shortens runway by raising monthly expenses, which should be checked against the fundraising timeline.
- Cost-cutting decisions — modeling how much runway a specific expense reduction actually buys.
- Board and investor updates — runway is one of the standard health metrics reported at every board meeting.
How to Use This Calculator
- Enter the Current Cash Balance ($).
- Enter Monthly Expenses ($).
- Enter Monthly Revenue ($, optional) if the company has any incoming revenue.
- Select Calculate to see runway in months, or a cash-flow-positive result if revenue covers expenses.
Related Calculations
See exactly how the burn figure was derived with the Burn Rate Calculator, or review the full cash movement behind it with the Cash Flow Calculator.