Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Runway including receivables
25.1
Runway on cash alone
8.7
Effective available cash
$301,400
Net monthly burn
$12,000
Collectible receivables
$197,400
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One click, a permanent link with your numbers baked in.
Got your number — what next?
Pick one, it takes 20 secondsHow to use this
- 1Enter cash on hand ($).
- 2Enter accounts receivable ($).
- 3Enter realistic collection rate (%).
- 4Enter accounts payable due ($).
- 5Enter monthly operating cost ($).
- 6Enter monthly collected revenue ($).
- 7Read your runway including receivables on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
Runway for a services business isn't just cash divided by burn, because a large slice of your near-term money is sitting in receivables that clients will pay on their own schedule. This calculator adds collectible receivables — discounted for your realistic collection rate — to cash on hand, subtracts payables due, then divides by net monthly burn to give a runway figure that survives contact with reality. It also shows the runway you'd have on cash alone, so you can see exactly how much of your survival depends on clients paying on time. Agencies on net-60 terms routinely find their honest runway is two months shorter than their bank balance implies.
Worked example
Using the values the calculator loads with:
Inputs
- Cash on hand: 150000 $
- Accounts receivable: 210000 $
- Realistic collection rate: 94 %
- Accounts payable due: 46000 $
- Monthly operating cost: 98000 $
- Monthly collected revenue: 86000 $
Results
- Runway including receivables: 25.1
- Runway on cash alone: 8.7
- Effective available cash: $301,400.00
- Net monthly burn: $12,000.00
- Collectible receivables: $197,400.00
What each field means
Inputs
- Cash on hand ($)
- The cash on hand used in the calculation, measured in $. Starts at 150000 $ so you have a working example on load.
- Accounts receivable ($)
- The accounts receivable used in the calculation, measured in $. Starts at 210000 $ so you have a working example on load.
- Realistic collection rate (%)
- The realistic collection rate used in the calculation, measured in %. Starts at 94 % so you have a working example on load. Accepted range: 0–100 %.
- Accounts payable due ($)
- The accounts payable due used in the calculation, measured in $. Starts at 46000 $ so you have a working example on load.
- Monthly operating cost ($)
- The monthly operating cost used in the calculation, measured in $. Starts at 98000 $ so you have a working example on load.
- Monthly collected revenue ($)
- The monthly collected revenue used in the calculation, measured in $. Starts at 86000 $ so you have a working example on load.
Results
- Runway including receivables
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Runway on cash alone
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Effective available cash
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Net monthly burn
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Collectible receivables
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Should I really count receivables as runway?
Count them, but discount them — by your historical collection rate and, if you're being careful, by ageing bucket. Invoices over 90 days old collect at materially lower rates than current ones, so a single blended rate flatters an old ledger.
What runway should a services business hold?
Three months is the common minimum, six is comfortable, and anything under two months makes you a price-taker in every renewal negotiation because you can't afford to walk away.
How do I extend runway fastest?
Collections beat cost cuts on speed. Chasing overdue invoices, moving new contracts to 50% upfront, and switching to milestone billing can pull weeks of cash forward in days, whereas headcount reductions take a notice period to show up.
Why does runway show 999?
Because your collected revenue already covers operating cost, so there is no burn to divide into. You're cash-flow positive at the numbers entered.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
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Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Services Business Cash Runway Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/agency-runway-months
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/agency-runway-months" target="_blank" rel="noopener">Services Business Cash Runway Calculator — RevenueLab</a> (2026).</p>
Source: [Services Business Cash Runway Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/agency-runway-months) (2026).