How the startup runway calculator works
This free startup runway calculator shows how many months your company can operate before cash runs out. Enter your cash in the bank, gross monthly burn, and monthly revenue - the calculator models your cash balance month by month, including revenue growth, and shows the date your balance hits zero. No signup is required, and results are shareable and embeddable via URL.
Runway is the most-watched number at every accelerator: it determines when you must start fundraising and how aggressive your hiring plan can be.
The formulas
Net monthly burn = gross monthly burn - monthly revenue
Gross burn is your total monthly spending; net burn subtracts the revenue that offsets it.
Runway (months) = cash in bank / net monthly burn
With growing revenue, effective runway extends beyond this simple division - the calculator models that month by month.
Benchmarks founders should know
- Post-seed runway target: 18-24 months - what most accelerators advise a seed round should buy
- Minimum safe runway: 6 months - below this, fundraising happens under pressure and terms suffer
- Time to close a round: 3-6 months - so start fundraising at 9-12 months of remaining runway
Frequently asked questions
What is startup runway?
Runway is the number of months a startup can keep operating before it runs out of cash. It is calculated by dividing cash in the bank by net monthly burn (gross burn minus monthly revenue).
What is a good runway for a pre-seed or seed startup?
Most accelerators recommend raising enough for 18-24 months of runway. That gives roughly 12-18 months to hit milestones and a 6-month buffer to close the next round.
When should I start fundraising?
Start when you have 9-12 months of runway left. A typical seed round takes 3-6 months to close, and negotiating with under 6 months of cash weakens your leverage.
What is the difference between gross burn and net burn?
Gross burn is total monthly spending. Net burn subtracts monthly revenue. Runway should be calculated on net burn, but be conservative about revenue growth assumptions.
Is this runway calculator free?
Yes. The Accelerator.tools runway calculator is completely free, requires no signup, and results can be shared or embedded via URL.
Last updated July 2026 by the Accelerator.tools editorial team. Explore more free tools in the calculator library or browse the community-voted tool directory.