Cash Runway Calculator
How many months you can operate at your current burn — and what breaks first.
Your numbers
Your result
- Total monthly cash out
- $140,500
- Net monthly cash flow
- -$22,500
- Cash runway (bank only)
- 3.8 mo
- Runway with credit line & receivables
- 11.3 mo
- Collections needed to break even on cash
- $140,500
- 3-month reserve target
- $421,500
- Short of a 3-month reserve by
- $336,500
- Months of reserve you currently hold
- 0.6 mo
About 3.8 months of runway.
You're burning about $22,500 a month. Collections are the fastest lever — deposits, faster invoicing, tighter terms — followed by the owner draw and any discretionary overhead. Do not solve this with more revenue at a thin margin; growth consumes cash before it produces it.
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What this number actually tells you
Profitable businesses go under all the time. Not because they weren't making money, but because the money arrived after the bills did. Cash runway is the number of months you can keep operating at your current burn rate, and it's the single most important number in a tight quarter.
The distinction that matters is cash collected versus revenue booked. Revenue is a promise. Collections are cash. If you invoice on net 30 and your customers pay on net 45, growth actively drains your account — every new job funds materials and payroll weeks before the deposit clears.
Two numbers to hold: months of runway if things stay as they are, and months of reserve you're carrying. Three months of operating expenses in a separate account is the target.
How the math works
- 01Total monthly cash out = materials + subs + field labor + overhead + payroll + debt service + owner draw + tax set-aside.
- 02Net monthly cash flow = cash collected − cash out.
- 03Burn rate = the absolute value of negative net monthly cash flow.
- 04Cash runway (months) = cash on hand ÷ burn rate.
- 05Reserve target = monthly cash out × 3. Months of reserve held = cash ÷ monthly cash out.
What to do with the answer
- Update this weekly during a tight stretch and monthly otherwise. Cash problems announce themselves early if anyone's looking.
- Fix collections before cutting costs: deposits on larger jobs, invoice the day work completes, and call anything past 30 days.
- Keep the reserve in a separate account at a different bank. Visible money gets spent.
- Count the credit line as emergency oxygen, not runway. Financing a burn rate turns a cash problem into a debt problem.
Want someone to read these numbers with you?
The Growth Assessment is a 30-minute conversation about what your numbers are telling you and what to fix first. No pitch deck, no PDF.
Schedule Your Growth Assessment Or call (737) 888-0415Questions owners ask about this
How much cash should a small business keep on hand?
Three months of total operating expenses is the standard target, six if your revenue is seasonal or project-based. Most small businesses run under one month, which is why an equipment failure or one slow month becomes a credit-line event.
What's the difference between profit and cash flow?
Profit is revenue minus expenses on paper. Cash flow is money in and out of the bank. Receivables, inventory, deposits, debt principal and equipment purchases all move cash without matching profit, which is why a profitable month can leave you short.
Why does growth hurt cash flow?
Because you pay for labor and materials before customers pay you. Every dollar of growth ties up cash in receivables and work in progress. That's why fast-growing businesses with thin margins run out of money — the growth itself is consuming it.
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