About this tool
Burn Rate & Cash Runway Calculator is a free, in-browser tool for founders and startups that shows how fast you are spending cash and how long it will last. Enter your cash balance, monthly operating expenses and any monthly revenue, and runway is projected instantly — all computed on your device with nothing uploaded.
Gross burn is your total monthly expenses. Net burn is expenses − revenue, the cash you actually lose each month. Cash runway = cash balance ÷ net burn, the number of months until you run out at the current pace. The tool projects an out-of-cash date by adding that many months from today. If revenue meets or exceeds expenses, net burn is zero or negative — you are cash-flow positive and there is no runway limit.
Use it to plan fundraising and hiring: a common rule is to raise before runway drops below six months. Lowering expenses or lifting revenue both extend the date — adjust the inputs to model each lever.