Burn & Runway Calculator
Runway = Cash ÷ Net Monthly Burn. Net burn = Monthly Operating Cost − Monthly Gross Profit. Healthy SaaS targets 18+ months runway. Below 12 months: focus burn reduction or fundraising. Marketing spend changes runway directly — every ₹1L/month change shifts runway by months.
- Runway = Cash ÷ Net Monthly Burn.
- Net burn = expenses minus gross profit.
- 18+ months: healthy. 12-18: monitor. Below 12: act.
Salaries + tooling + ops + marketing
Theoretical floor
Net Burn = Opex − (Revenue × Gross Margin) · Runway = Cash ÷ Net Burn- Use net burn (after gross profit), not gross burn.
- Marketing-zero runway shows the floor — useful for crisis planning.
- Below 12 months: cut burn or close funding round.
- Above 24 months: consider deploying more into growth.
Frequently asked questions
Should I use gross or net burn?
Net burn — operating expenses minus gross profit (revenue × gross margin). Gross burn ignores revenue offset and overstates runway need.
How does marketing spend affect runway?
Marketing is a major operating expense. ₹1L/month increase in marketing reduces runway by ~Cash÷₹1L months. Plan marketing as % of cash, not just % of revenue.
When is short runway acceptable?
Pre-Series A startups commonly run 6-12 month runway expecting next round. Below 6 months: close that round or stop spending. Above 24 months: possibly under-investing in growth.
Should I include reserved cash?
Yes if reserved for known liabilities (taxes, vendor payables). Don't include if reserved 'just in case' — that's psychological reserve, not actual liability.
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