Burn rate calculator: net burn and cash runway
This burn rate calculator shows how fast your company spends cash and how long the money in the bank lasts at that pace. Enter your current cash, the cash coming in each month and the cash going out.
Gross burn, net burn and runway
Gross burn is all the cash that leaves the business in a month. Net burn is gross burn minus the cash that comes in, so it is how much your bank balance actually drops each month. Runway is how many months that balance lasts:
Net burn = cash out per month − cash in per monthRunway (months) = cash in the bank ÷ net burn
Use cash, not accounting profit. A customer invoice you have not been paid for does not pay salaries, and a yearly software bill paid up front leaves the bank this month even though the accounts spread it over twelve.
A worked example
With 450,000 in the bank, 38,000 coming in and 70,000 going out each month, net burn is 32,000. Runway is 450,000 ÷ 32,000 = 14.1 months. If you plan to raise money or reach break-even, that is the window you have, and fundraising usually takes several months of it.
Keeping runway honest
Use an average of the last three months rather than one month, because a single month can include a yearly bill or a large customer payment. Recalculate after every hire, price change or large contract. For a forward view week by week, a 13-week cash flow forecast is the better tool.
Teams that track this monthly usually rebuild it in a spreadsheet from the bank and accounting exports. A CFO dashboard can show the same cash position and forecast every morning without anyone rebuilding it; see how I build live data dashboards.
Burn rate calculator: questions answered
Need this number live, every month? Ask me, I reply within a few hours on working days.
What is burn rate?
Burn rate is the speed at which a company spends its cash, usually per month. Gross burn is all cash going out; net burn is cash going out minus cash coming in. Net burn tells you how much the bank balance falls each month, which is what decides your runway.
How do you calculate cash runway?
Divide the cash you have in the bank by your monthly net burn. With 450,000 in the bank and a net burn of 32,000 a month, runway is about 14 months. It assumes the current month repeats, so recalculate whenever costs or revenue change.
What is the difference between gross burn and net burn?
Gross burn is total monthly cash spending: salaries, rent, suppliers and tools. Net burn subtracts the cash that comes in from customers and other income. A company with high gross burn can still have a low net burn if revenue covers most of its costs.
How much runway should a company have?
Many founders aim for at least 12 to 18 months of runway, because raising money or cutting costs takes time to show results. The right amount depends on how predictable your revenue is and how long it takes to close funding or large customers in your market.
Is my data stored when I use this calculator?
No. The calculator runs entirely in your browser. The numbers you type are not sent to a server, not stored and not tracked. Close the page and they are gone.