Startup Runway Calculator

This startup runway calculator works out how long a company's cash will last. Enter cash on hand and monthly net burn to get the months remaining and the month the money runs out. If spending is going to rise, add a monthly growth rate for burn and the calculator works the runway out month by month.

How to Calculate Runway

A company with $500,000 in the bank and a net burn of $40,000 a month has 500,000 ÷ 40,000 = 12.5 months of runway.

Net burn is spending minus revenue. If you need to work it out first, the Burn Rate Calculator builds it from monthly expenses.

Runway When Burn Is Growing

The simple formula assumes burn never changes. In a company that is hiring, it rises every month, and each rise brings the end date closer. The calculator handles this by subtracting each month's burn in turn and raising it by the growth rate you enter.

A 5% monthly rise costs more than two and a half months of runway here. Revenue growth works the other way: if revenue rises faster than costs, net burn falls and the runway is longer than the simple figure. Enter a negative growth rate to model that.

What Counts as Cash

• Count: money in business bank accounts and deposits you can withdraw at once.
• Do not count: investment that has been agreed but not paid in.
• Do not count: invoices that customers have not paid yet.
• Do not count: a credit line you have not drawn.

Runway is a measure of what is certain. Anything that still depends on someone else paying is a way to extend runway later, not part of it today.

How Much Runway Is Enough?

Enough to reach the next point at which the company can raise money or pay its own way, with time to spare for the raise itself. Fundraising commonly takes several months from first meetings to money in the bank, so a company that starts looking with four months of cash is negotiating under pressure. The often-quoted 12 to 18 months is a convention among founders and investors, not a rule; the right figure depends on how far away the next milestone is.

Ways to Extend Runway

Only two things change the figure: more cash or less net burn. Cutting costs takes effect from the month the cut is made. New revenue lowers net burn too, but usually takes longer to arrive. Raising money or borrowing adds to cash on hand and leaves burn unchanged. Re-run the calculator with the new burn or cash figure to see what each option buys in months.

How to Use the Runway Calculator

1. Enter cash on hand: Type the total cash in the business bank accounts today.
2. Enter monthly net burn: Type how much the cash balance falls each month: spending minus revenue.
3. Read the runway: The calculator shows the months of cash left and the month it runs out.
4. Add burn growth: Optional. Open the growth setting and enter the percentage by which burn rises each month to see the shorter runway.

Frequently Asked Questions