Free tool · Cash flow
Cash runway calculator
How long can the business keep going at today's pace? Enter the cash you have and what comes in and goes out each month for your burn rate, months of runway and a month-by-month projection. Runs in your browser; nothing is saved.
Your cash
All business accounts. Leave out an unused line of credit, or add it to see the worst case.
Customer payments actually received, not sales invoiced.
Payroll, rent, suppliers, loan payments, taxes, owner draws.
Runway
Net burn this month
Cash out − cash in
$9,000.00
Months of runway
9.4 months
Cash runs out around
Aug 2027
A straight-line projection from the figures you enter. Real months are lumpy: tax payments, annual insurance, seasonal sales. Works in any currency.
Month by month (first 12 months)
| Month ending | Cash in | Cash out | Closing cash |
|---|---|---|---|
| Nov 2026 | $22,000.00 | $31,000.00 | $76,000.00 |
| Dec 2026 | $22,000.00 | $31,000.00 | $67,000.00 |
| Jan 2027 | $22,000.00 | $31,000.00 | $58,000.00 |
| Feb 2027 | $22,000.00 | $31,000.00 | $49,000.00 |
| Mar 2027 | $22,000.00 | $31,000.00 | $40,000.00 |
| Apr 2027 | $22,000.00 | $31,000.00 | $31,000.00 |
| May 2027 | $22,000.00 | $31,000.00 | $22,000.00 |
| Jun 2027 | $22,000.00 | $31,000.00 | $13,000.00 |
| Jul 2027 | $22,000.00 | $31,000.00 | $4,000.00 |
| Aug 2027 | $22,000.00 | $31,000.00 | -$5,000.00 |
How cash runway is calculated
- Net burn = cash out in a month − cash in.
- Runway = cash today ÷ net burn, when the monthly figures stay the same.
- With growth rates, each month's cash in and cash out grow by the rate you enter, the closing balance is carried forward, and runway is the point in the month where the balance reaches zero.
- If cash in is more than cash out, there is no burn and the cash does not run out at these numbers.
Worked example
A design studio has $85,000 in the bank. Clients pay about $22,000 a month, and payroll, rent, software and the owner's draw come to $31,000. Net burn is $9,000 a month, so runway is 9.4 months. If costs grow 1% a month from a new hire, the runway falls to about 8 months. Winning one $3,000-a-month retainer cuts net burn to $6,000 and stretches the runway to 14 months.
Getting the inputs right
- Average three to six months of real bank activity rather than guessing. Leave out one-off items, then think about the ones coming up.
- Include cash that is not an expense: loan principal, equipment you pay for in cash, owner draws, sales tax and payroll taxes you pass on.
- Plan for lumpy months: quarterly estimated tax or instalments, annual insurance, year-end bonuses, a slow season.
- Count only cash you can use. Money held for sales tax or payroll remittances is not runway.
For the balance-sheet view of the same question, use the working capital calculator. To plan in detail month by month, the cash flow forecast template has a row for every kind of receipt and payment.
Questions
How do I calculate cash runway?
Cash runway = cash in the bank ÷ net monthly burn, where net burn = cash going out each month − cash coming in. With $85,000 in the bank, $22,000 coming in and $31,000 going out each month, net burn is $9,000 and runway is $85,000 ÷ $9,000 = 9.4 months.
What is the difference between gross burn and net burn?
Gross burn is everything that goes out in a month: payroll, rent, suppliers, loan payments, taxes. Net burn is gross burn minus the cash that comes in. Runway uses net burn; gross burn tells you how long you would last with no sales at all.
Should I use profit or cash?
Cash. A business can be profitable on paper and still run out of money if customers pay slowly, stock builds up or loan principal is due (principal repayments are not an expense on the profit and loss, but they are cash out). Use what actually lands in and leaves the bank.
How much runway should a small business have?
Many owners aim for three to six months of expenses in reserve when the business is steady, and more when sales are seasonal or uncertain. With under six months, it is time to act: arranging a loan or line of credit takes weeks, and lenders prefer to lend before cash is tight.
How do growth rates change the answer?
If cash out grows faster than cash in (hiring ahead of sales, rising costs), runway shrinks faster than the simple division suggests. Enter a monthly growth rate for each and the calculator projects month by month and finds the month the balance goes below zero.
What can I do to extend runway?
Collect faster (deposits, shorter terms, reminders), cut or delay costs that do not bring in sales, sell slow stock, negotiate longer supplier terms, and line up financing before you need it. Every $1,000 of monthly burn removed adds runway at once.
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A planning estimate, not financial advice.
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