Startup Burn Rate Calculator & Runway Forecaster
Model your startup's monthly gross burn, net burn, revenue growth, and cash runway months. Interactive scenario planning with zero-cash date countdown. 100% confidential and calculated in your browser.
Balance & Monthly Cash Flow
Monthly Operating Expenses (Gross Burn)
What Is Burn Rate and Why Is Runway the Ultimate Survival Metric?
For early-stage technology startups and indie founders, cash runway is the single most vital operational metric. Your runway dictates exactly how many months your team has to reach product-market fit, achieve profitability, or secure the next investment tranche before the bank account reaches zero. Failing to account for compounding server infrastructure costs, contractor salaries, or seasonal dips in growth is the leading cause of premature startup failure.
The Exact Mathematical Formulas Behind Burn Rate
- Gross Burn Rate:
Total Monthly Expenses = Salaries + Servers + Marketing + Office/Tools. - Net Burn Rate:
Gross Burn Rate - Monthly Revenue (MRR). This represents actual monthly cash depletion. - Static Runway (Months):
Cash in Bank / Net Burn Rate. - Dynamic Compound Runway: Incorporates monthly revenue growth percentages (
MRR * (1 + Growth)^t) to accurately forecast when a startup reaches the default-alive inflection point.
Why Use ZeroCostAI's Startup Burn Rate Calculator?
- 100% Client-Side Privacy: Your sensitive financial metrics and payroll figures remain on your device and are never sent to external servers.
- Dynamic MoM Revenue Growth Modeling: Avoid pessimistic static models by simulating how customer acquisition offsets monthly burn over time.
- Zero-Cash Date Countdown: Visualizes the exact calendar month when fundraising or break-even milestones must be reached.
- 1-Click Clipboard Export: Copy formatted investor update notes in seconds.
Frequently Asked Questions
What does 'Default Alive' mean?
Coined by Paul Graham of Y Combinator, a startup is 'Default Alive' if its current revenue growth rate will allow it to reach cash-flow break-even before running out of money, without requiring additional funding rounds.
When should a founder begin raising their next round?
Standard venture guidance is to begin investor conversations when you have between 6 and 9 months of runway remaining. Closing a priced equity round or convertible note typically takes 3 to 6 months.