runway: definition
The number of months your cash will last at the current spending rate before you run dry.
By Isidore Mikorey-Nilsson · June 20, 2026
Definition
Runway is your track before takeoff or crash: available cash divided by the monthly net loss (the burn). It sets the tempo for all your acquisition decisions: a short runway forces fast-return channels and a tight payback; a comfortable runway allows slower bets like inbound. Watching it keeps you from hitting a wall.
How to calculate it
Runway (in months) = available cash / monthly net loss (burn)
Why it matters
Runway dictates which acquisition channels you can afford: with six months ahead of you, you cannot bet on SEO that takes a year to pay off. Knowing it means avoiding death by the right strategy applied at the wrong time.
When to use it
You calculate and monitor it constantly, especially before increasing spend. In practice, before launching a slow channel, you check that your runway comfortably covers its payback period, otherwise you pick a faster lever.
Example
With 60,000 euros in the bank and a loss of 10,000 euros a month, your runway is six months.
Common mistakes
- Launching a slow channel with too little runway.
- Forgetting upcoming expenses when calculating burn.
- Recalculating it too rarely.
Don't confuse it with
- payback: Runway is the company's overall survival time; payback is the time it takes for an acquired customer to become profitable.
Related terms
Articles that use this term
Frequently asked questions
- What runway should you keep as a safety margin?
- Many founders aim for at least 12 to 18 months, giving themselves time to test channels without deciding under pressure.