Cash runway and burn rate calculator
Find out how many months your cash will last at today's spending, and what it would take to reach the runway you want.
How it's calculated
Net burn is the cash going out each month minus the cash coming in. Runway is your cash balance divided by that net burn. If more comes in than goes out, you're cash-flow positive and the runway is open-ended.
Worked example
A business has 120,000 in the bank, receives 40,000 a month and pays out 52,000. Net burn is 12,000 a month, so the runway is 10 months. To reach 12 months, it would need to cut net burn to 10,000 a month, or add 24,000 of cash.
Make the figures realistic
- Use the average of the last three months, not your best month
- Include tax payments, loan repayments and owner drawings, not just running costs
- Leave out one-off receipts you can't count on again
- Plan for timing: a big customer paying late shortens your runway overnight
This is a quick check. For week-by-week visibility, use our free 13-week cash flow template.
Common questions
What is a healthy cash runway?
It depends on how predictable your income is. Loss-making and early-stage businesses often aim for 12 months or more. Profitable, steady businesses commonly keep a buffer of two to three months of costs.
What's the difference between gross burn and net burn?
Gross burn is everything you spend in a month. Net burn is what you spend minus what you receive. Runway uses net burn.
How do I extend my runway quickly?
Collect what customers owe you, agree longer terms with suppliers, pause non-essential spending and review prices. A cash flow forecast shows which of these matters most.
Step one is free
Fix the leaks. Build the company.
Start with a free 20-minute Leak Check, online, wherever you are. Tell us where money feels tight and we'll show you where it's slipping away.
Or email info@sfglobalconsulting.com, or DM “LEAK” to @shazfinedge on Instagram.