Burn Rate and Runway: What Every Startup Founder Should Track Monthly
Two numbers determine how much time you have before you need to raise again — or become profitable. Here's how to calculate and use them.
What is Burn Rate?
Burn rate is the rate at which your startup spends cash, typically expressed monthly. "Gross burn" is total monthly expenses, while "net burn" subtracts any revenue — net burn is usually the more meaningful number for early-stage companies.
What is Runway?
Runway is simply your current cash balance divided by your monthly net burn rate — it tells you how many months you have before running out of cash at the current spending rate.
Why This Matters Beyond the Obvious
Runway isn't just about survival — it determines your negotiating position. A founder with 18 months of runway has far more leverage in fundraising conversations than one with 3 months left, because they're not raising from a position of desperation.
How Burn Rate Changes Over Time
As you hire, burn rate typically increases. Modeling how burn rate will change based on planned hires and spending — not just looking at the current month — gives a more accurate runway projection.
The Connection to Monthly Bookkeeping
Burn rate and runway calculations are only as good as the underlying financial data. Clean, current monthly books mean your burn rate calculation reflects reality, not a rough estimate from three months ago.
Burn Multiple
A newer metric some investors look at is "burn multiple" — net burn divided by net new revenue added in the same period. A lower burn multiple suggests more capital-efficient growth, and benchmarks vary by stage but generally below 2x is viewed favorably for growth-stage companies.
Scenario Planning for Runway
Rather than a single runway number, modeling 2-3 scenarios (current plan, reduced spend, accelerated hiring) shows the range of possible outcomes and helps founders understand which spending decisions have the biggest impact on runway — informing prioritization conversations.
When to Start Fundraising Relative to Runway
A common guideline is to begin fundraising when you have 6-9 months of runway remaining, since the fundraising process itself typically takes 3-6 months. Waiting until runway is critically short puts founders in a weak negotiating position.
