How do you calculate runway?
Runway is cash on hand divided by monthly net burn. Net burn is monthly expenses minus monthly revenue. For example, $240K in cash and a $30K monthly net burn gives 8 months of runway.
Free startup tool
Runway & Burn Rate Calculator
Enter your cash, monthly expenses and revenue to instantly see how many months of runway your startup has. Then test the same decision in the simulation.
Enter cash and expenses to compute your runway instantly.
Test this in the simulation →Runway (months) = Cash on Hand ÷ Monthly Net Burn · Net Burn = Monthly Expenses − Monthly Revenue
How it works
1
Find net burn
Subtract monthly revenue from monthly expenses. What remains is your monthly net cash burn.
2
Divide by cash
Divide cash on hand by monthly net burn. The result is how many more months you can operate.
3
Act on the threshold
18+ months is healthy, under 12 means fundraise, under 6 is a defense signal.
Frequently asked questions
What is burn rate?
Burn rate is a startup's monthly net cash spend. Gross burn is total expenses, while net burn subtracts revenue from expenses. Runway is calculated using net burn.
How many months of runway is healthy?
Founders usually target 18–24 months between rounds, because preparing and closing the next round can take 6–9 months. Below 12 months you shift to fundraising; below 6 months you shift to defense.
How do I extend runway?
Two levers: cut spend (slow hiring, remove unused tools) or grow revenue (pricing, annual prepay, faster collection). New capital is a third lever, but if you do not know why you are burning, it only makes the mistake more expensive.
Test the decision in the simulation
In Founder Runway every decision moves Cash and Runway. Test an aggressive hiring plan, an early sales team, or a bridge round safely — not with real money.