Runway is the amount of time your business can operate before it runs out of cash, assuming current income and expenses stay the same. It’s among the most critical metrics for startups and finance teams, especially during fundraising, high-growth phases, or market uncertainty.
Runway gives founders and operators a direct answer to a high-stakes question: How many months do we have left before we need more cash?
How to Calculate Runway
The most common formula:
Runway (in months) = Cash Balance ÷ Net Burn Rate
Where:
- Cash Balance is the total liquid cash available
- Net Burn Rate is how much cash the business is losing each month (expenses minus revenue)
Example:
If you have $500,000 in the bank and you’re burning $50,000 per month, your runway is:
$500,000 ÷ $50,000 = 10 months
That means, without changes, you have 10 months until you run out of cash.
Burn Rate vs. Runway: Know the Difference
- Burn rate tells you how fast you’re spending money.
- Runway tells you how long you can keep going at that pace.
Understanding both is essential. A $1M burn rate might be fine if you have $20M in the bank. But it’s a problem if you only have $300K.
3-Month Runway Trend: Why It Matters
Tracking your runway trend over the past three months (or longer) helps you spot financial shifts early. Are you extending your runway through new revenue or shortening it through increased spending?
Here’s what to look for in your trend:
- Runway increasing? Likely due to reduced burn or increased revenue.
- Runway shrinking? You’re either spending more or earning less, and it’s time to take a closer look.
- Flat Runway? No big changes, but that might not be sustainable if funding is needed soon.
A flat or shrinking runway means you may need to raise capital, cut costs, or rethink growth plans before cash runs out.
Types of Runway to Track
- Cash Runway – Purely based on bank balance and monthly burn
- Revenue-Adjusted Runway – Accounts for projected revenue growth
- Scenario-Based Runway – Models different paths (hiring freeze, marketing cutbacks, new sales)
Each version offers a different lens. The right one depends on how stable your revenue is and how aggressive your spending plans are.
Strategic Use of Runway
Runway isn’t just a finance metric—it’s a decision-making tool. Use it to:
- Time your next fundraiser strategically
- Set growth targets and hiring plans responsibly
- Align your team on budget priorities
- Reassure investors with disciplined cash management
Startups that manage runways well don’t just survive, they create space to grow without panic.
Wondering if your current runway is realistic or how to improve it before your next round? Durity can help. We bring clarity to your burn rate, runway trends, and financial forecasting—so you can make smarter decisions and raise capital confidently, backed by clean numbers and real insight.
