Runway is the amount of time a startup can continue operating before it exhausts its available cash, typically measured in months. The calculation is straightforward: divide current cash reserves by the monthly burn rate (the amount spent each month beyond revenue). For example, a company with $600,000 in the bank burning $50,000 per month has a 12-month runway.
This metric serves as a startup's financial countdown clock. Founders track runway obsessively because it determines when they must either raise additional capital, achieve profitability, or shut down. Investors scrutinize runway during due diligence to assess urgency and timing. A company with 18 months of runway has breathing room to execute its plan and negotiate favorable terms, while one with 4 months faces desperate circumstances that often lead to unfavorable down rounds or fire sales.
Why It Matters
Runway directly impacts investment decisions and valuation negotiations. Investors prefer companies with at least 12-18 months of runway because this timeframe allows sufficient room to hit milestones and raise the next round from a position of strength. Short runway creates leverage problems: founders with only 3-4 months remaining have little negotiating power, often accepting lower valuations or onerous terms. Understanding a company's runway also helps investors time their entry and anticipate when the startup will return to market seeking additional capital.
Example
Consider a SaaS startup with $900,000 in cash reserves. The company generates $20,000 in monthly recurring revenue but spends $95,000 monthly on salaries, marketing, and operations. The net burn rate is $75,000 per month ($95,000 minus $20,000). The company's runway is 12 months ($900,000 divided by $75,000). The founders know they need to begin fundraising conversations in month 6 or 7, as closing a round typically takes 4-6 months. If they wait until month 10, they risk running out of cash mid-process, forcing them to accept unfavorable terms or bridge financing at high cost.