Burn Rate & Runway Calculator
Monthly cash burn and how long your runway lasts. Enter cash balance and recent expenses; get net burn, gross burn, and runway in months.
About the Burn Rate & Runway Calculator
The Burn Rate & Runway Calculator is the most important spreadsheet a startup operator runs every month. It computes how fast cash is leaving the business (burn rate) and how many months you can keep going at the current pace (runway). Both numbers determine fundraising urgency, hiring decisions, and your negotiating position with investors.
The tool separates gross burn (total cash going out) from net burn (cash going out minus revenue coming in). Net burn is what determines runway. The growth-mode projection then layers expected revenue increases on top, showing how runway extends if you hit plan and compresses if you miss - a much more honest picture than "we have 12 months" assuming a flat world.
Common use cases
- Decide whether you need to raise now or have time to wait
- Stress-test runway against missing your revenue plan by 20%
- Justify a hiring freeze or new headcount to the board
- Communicate runway transparently to senior team members
Tips for accurate results
Always run a stress scenario where revenue drops by 10-20% from plan and gross burn stays flat. Markets and sales cycles deteriorate faster than expenses, and the gap between best-case and stress-case runway tells you how much margin for error you actually have. Below 6 months of stress-tested runway, you are in fundraise-or-cut-now territory.
Privacy & data handling
The Burn Rate & Runway Calculator runs entirely in your browser. Nothing you enter is uploaded, logged, or shared with third parties - the math happens locally and your inputs disappear when you close the tab. There is no signup, no email collection, and no daily-use limit.
What's the difference between gross burn and net burn?
Gross burn is total monthly cash outflow - every dollar leaving the bank. Net burn is gross burn minus revenue, so it's how fast your runway actually shrinks. A startup with $100k revenue and $300k expenses has $300k gross burn but only $200k net burn. Investors care about net burn for runway math.
How is runway calculated?
Runway = current cash ÷ monthly net burn. The tool also shows a more conservative version using a trailing 3-month average burn (smooths over one-off spikes) and a "stress-tested" version assuming revenue holds flat or drops 10%.
What runway should I keep on hand?
Conventional wisdom: 12 months minimum, 18-24 months ideal. Below 6 months you're in fundraise-now territory and lose negotiating leverage. Healthy companies typically maintain 18-24 month runway to absorb hiring mistakes, lost deals, and macro shocks without panic.
How can I extend runway without raising?
Three levers: (1) cut variable costs first - ads, contractors, non-essential SaaS subscriptions; (2) freeze hiring and let attrition reduce headcount; (3) raise prices on existing customers, since price increases compound monthly. Payroll is the slowest lever and the most painful, save it for last.
How does ramping growth affect runway?
Growing revenue stretches runway non-linearly because each new dollar of MRR reduces net burn for every future month. The tool's growth-mode projection lets you input expected monthly revenue growth and see how runway extends if you hit plan - and compresses if you miss.
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