Free tool
Cash runway calculator
Enter your cash balance and a typical month's revenue and expenses. The calculator shows how many months the cash lasts at that net burn, and the month it runs out. The formula is below the form. With JavaScript on, the figures you type stay in your browser.
Updated
Your runway
Runway
8.3 months
Cash runs out in June 2027
Net burn 30,000.00 a month
Rounded down to one decimal.
Runway
Cash-flow positive
Revenue covers expenses (net cash flow + a month), so at these figures the cash does not run out.
Runway
0 months
There is no cash left and the business still burns a month.
Runway
More than 50 years
At a net burn of a month the cash lasts longer than this calculator counts.
How it is calculated
net burn = monthly expenses - monthly revenue runway = cash balance / net burn (months, rounded down to 0.1) zero-cash month = the month the balance is from + (runway rounded up - 1) months
Worked example. 250,000 of cash, 40,000 of revenue and 70,000 of expenses a month give a net burn of 30,000. 250,000 / 30,000 = 8.33, so the runway is 8.3 months. Eight full months use 240,000; the last 10,000 runs out during the ninth month, so with October as month one the cash runs out in June.
If revenue is equal to or higher than expenses there is no burn, and the calculator reports the business as cash-flow positive instead of dividing by zero or by a negative number.
Getting the inputs right
- Use cash, not profit. Revenue here means cash actually collected, and expenses mean cash actually paid, including loan repayments and equipment, which a profit and loss leaves out.
- Average a few months. One month can be lumpy. The average of the last three gives a steadier burn; use the latest month if the business has just changed shape.
- Count only cash you can spend. Leave out deposits held for customers and balances you cannot reach.
- Rerun it after every big change. A hire, a lost customer or a new contract moves the date more than any rounding does.
From one number to a 13-week view
A runway assumes the same burn every month. Ataski's Financial Analyst reads your books every month and builds a 13-week cash forecast with its minimum balance and headroom, beside a calendar of the open invoices and bills falling due each week, so the dips between month ends are visible too.
Questions
How is cash runway calculated?
Runway in months = cash balance / net monthly burn, where net burn = monthly expenses - monthly revenue. The calculator rounds the result down to one decimal, so it never overstates the time left.
What if revenue is higher than expenses?
Then there is no burn: the business adds cash every month, and the calculator reports it as cash-flow positive instead of a runway.
Should I use gross burn or net burn?
Gross burn is everything you spend in a month; net burn is spending minus the cash that comes in. Runway is usually quoted on net burn. To see the gross-burn runway, enter 0 as monthly revenue.
How is the zero-cash month worked out?
The month your balance is from counts as month one. 100,000 of cash at a net burn of 30,000 lasts three full months and runs out during the fourth.
Why can the real runway differ from this figure?
The calculator assumes the same burn every month. Seasonal revenue, annual payments, payroll timing and customers paying late all move the date. A weekly cash forecast that places your open invoices and bills by their due dates shows those swings.