Startup Runway Calculator
Calculate startup runway months from cash on hand and burn rate.
See your zero-cash date and revenue needed to reach break-even from current spending.
Startup runway measures how many months a company can continue operating before running out of cash. It is one of the most critical metrics any founder must monitor.
The core formulas:
Monthly Burn Rate = Total Monthly Expenses − Monthly Revenue
Runway (months) = Current Cash Balance / Monthly Burn Rate
Zero Date = Today + Runway in Months
Months to Profitability = (Fixed Costs / Gross Margin per Unit) / Monthly New Customers
What each variable means:
- Burn Rate — net cash spent per month (gross burn = all expenses; net burn = expenses minus revenue)
- Cash Balance — total liquid cash and equivalents available right now
- Runway — the answer to “how long until we need more funding or revenue?”
- Zero Date — the specific calendar date when cash runs out if nothing changes
Worked example: A SaaS startup has $420,000 in the bank. Monthly expenses: $85,000 (salaries, servers, marketing). Monthly recurring revenue: $22,000.
Net burn = $85,000 − $22,000 = $63,000/month Runway = $420,000 / $63,000 = 6.67 months ≈ 6.5 months of runway Zero date: approximately 6–7 months from today
Rule of thumb benchmarks:
- Safe runway: 18+ months
- Healthy runway: 12–18 months
- Danger zone: under 6 months
- Critical: under 3 months (start fundraising immediately)
Investors expect founders to raise their next round when 6 months of runway remain — fundraising typically takes 3–6 months, so you need a buffer. Reduce burn by deferring non-essential hires and negotiating vendor contracts before you hit the danger zone.