Cash runway calculator

Runway is the plainest question in business finance: if nothing changes, when does the money stop? Three numbers answer it. Knowing the answer early turns a future crisis into a planning decision, and it changes how lenders see you.

Inputs: three numbers from your bank account

• Cash in the bank now. The balance across business transaction and savings accounts you can actually spend. Leave out money already committed, such as GST collected that’s due on the next BAS.
• Monthly outgoings. Everything that leaves the account in an average month: wages, super, rent, suppliers, loan and lease repayments, PAYG instalments and owner drawings.
• Monthly income. Cash actually received, not invoices sent. A $40,000 invoice on 60-day terms isn’t this month’s income.

Average each figure across six to twelve months of statements for the most reliable picture. Accounting software works too, as long as you use the cash view, not accruals.

Outputs: what each line tells you

Months of runway. Cash divided by monthly burn, to one decimal place. If income is higher than outgoings, the calculator says “Cash positive” instead, and notes that finance may still help you grow faster.

Monthly burn. Outgoings minus income: the shortfall you’re funding from reserves each month.

Runs out around. Today’s date plus the runway, at roughly 30.4 days a month. It’s an estimate, not a deadline, but it’s a useful date to put in the diary.

Buffer for 3 months. How much extra cash you’d need to hold three months of burn in reserve. If you already have more than that, it reads $0 extra needed.

Below three months, the note changes to flag that now is the moment to arrange funding, while the numbers still look good to a lender.

Example: a café group in a quiet winter (illustrative)

A two-site café business in Hobart holds $140,000 across its accounts. Winter outgoings average $95,000 a month and takings average $78,000.

• Monthly burn: $95,000 − $78,000 = $17,000
• Months of runway: $140,000 ÷ $17,000 = 8.2 months
• Runs out around: early July 2027 (if calculated on 25 October 2026)
• Buffer for 3 months: $51,000 needed, already covered, so $0 extra needed

That’s comfortable. Now picture the same business after an unplanned $110,000 coffee machine and fit-out repair, leaving $30,000 in the bank. Runway drops to 1.8 months and the buffer line shows $21,000 extra needed. Same café, same trading, and suddenly a very different conversation with a lender.

If your runway is heading under three months, ask what’s possible before it gets tighter. It’s free and doesn’t involve a credit check.

Lumpy costs that make runway look longer than it is

An average month can hide cash cliffs. Check these before trusting the figure:

Cost	Why it distorts runway	Fix
Quarterly BAS	GST and PAYG land in one hit every three months	Average them across the quarter
Super	Under Payday Super (from 1 July 2026), contributions must land in employees’ funds within days of each pay run, not each quarter	Include super in every month’s wages figure
Insurance, rego, licences	Annual bills that don’t show in a typical month	Divide by 12 and add to outgoings
An ATO payment plan	A fixed instalment on top of new tax	Model it in the ATO debt calculator first
Christmas or EOFY	Seasonal dips in income and spikes in wages	Run a second scenario with the quiet-month income

The Payday Super change is worth a second look if you used to time big purchases around the quarterly super deadline. That float has gone: super now leaves the account with each payroll cycle.

How to lengthen runway, from cheapest to dearest

1. Collect faster. Shorter payment terms, deposits on new jobs and prompt follow-up of overdue invoices.
2. Trim or defer costs. Renegotiate supplier terms and pause discretionary spending.
3. Use what you’ve already invoiced. Invoice finance turns money owed by customers into cash now.
4. Set up a buffer facility. A business line of credit sits unused until a tight month, and you generally pay interest only on what you draw.
5. Borrow against property. For larger or longer gaps, a secured loan typically costs less over time than unsecured debt.

Your bank may well offer the cheapest version of options 4 and 5 if you meet its criteria, so start that conversation early. If it says no, non-bank lenders cover the same ground with different rules.

To size the hole between supplier bills and customer receipts, use the cash flow gap calculator. To check short-term liquidity overall, try the working capital ratio calculator.

Short runway? Use the time you still have

The owners with the most choice are the ones who ask while the bank balance still has some depth. Tell us your runway figure and what’s driving the burn. Budget about a minute. Your credit score doesn’t move because you asked, and your phone won’t light up with calls from strangers: the enquiry stays with us. A real person studies your figures and calls to work through the options. Put in honest monthly figures, including the costs you’d rather not think about, so the first suggestion is one that genuinely fits.

Talk to someone about my runway →