Enter your cash balance, monthly expenses and revenue to calculate your runway in months. Plan your fundraise before the clock runs out.
Startup runway is the number of months your company can continue operating before it runs out of cash. It is the single most important metric for any pre-profit startup — and the one investors ask about first.
Runway is calculated by dividing your current cash balance by your net monthly burn rate (total monthly expenses minus any monthly revenue). If you have £120,000 in cash and a net burn of £10,000 per month, your runway is 12 months.
This calculator models your runway dynamically — accounting for revenue growth over time, not just a static snapshot. That gives you a more realistic picture of when cash actually hits zero.
Founders and investors use two measures of burn rate, and it’s important to understand the difference.
Your total monthly operating expenditure — salaries, rent, software, cloud hosting, marketing, professional fees — regardless of revenue. This tells you how much cash is going out the door every month.
Your total monthly expenditure minus monthly revenue. This is the number that matters for runway because it shows how fast your cash balance is actually declining. A startup spending £20,000/month with £5,000 in revenue has a gross burn of £20,000 but a net burn of only £15,000.
Track both. Report gross burn to understand your cost structure. Use net burn for runway calculations and fundraising conversations. VCs will ask for both — and they’ll cross-reference against your management accounts.
There’s no universal answer, but most VCs and startup advisors converge on these benchmarks:
A typical fundraise takes 3 to 6 months from first pitch to cash in the bank. That means you should start the process when you have at least 6 to 9 months of runway remaining. Starting late forces you to accept worse terms or risk running dry mid-process.
If you’re raising under SEIS or EIS, build in extra time for HMRC advance assurance (4–6 weeks) and compliance statement processing.
Need help extending your runway or preparing to raise?
AccTek builds the financial infrastructure startups need — from Xero setup to investor-ready reporting.
If your runway is shorter than you’d like, there are two levers: reduce burn or increase revenue. Here’s where most startups find the biggest gains.
If you’re spending on R&D, you may be able to claim R&D tax credits — generating a direct cash payment from HMRC that extends your runway without dilution.
Real-time dashboards, management accounts and proactive tax planning — from a startup accountant that gets it.
This calculator provides estimates for planning purposes only. Actual runway depends on cash timing, tax obligations, payroll cycles and other factors. For personalised financial forecasting, book a free consultation with AccTek.
