Startup Runway Calculator

What is a startup runway calculator?

Runway is the single number founders watch most closely: how long until the money runs out. This calculator turns your cash balance, revenue and monthly expenses into a runway in months, an estimated cash-out date, and a chart of your cash balance over time.

How runway is calculated

• Net burn = Monthly cash outflow − Monthly revenue
• Runway (months) = Current cash ÷ Net monthly burn

If revenue meets or exceeds expenses, there is no finite runway — the calculator says you are cash-flow positive rather than showing an infinite number.

Scenario analysis

Runway is highly sensitive to small changes. The scenario table shows how your runway shifts with +10%/+20% revenue or −10%/−20% expenses, so you can see which lever buys you the most time before you need to raise or cut costs.

Example

With $500,000 in the bank and a net burn of $50,000 a month, you have 10 months of runway. Cutting expenses 20% (to a $40,000 net burn) would extend that to 12.5 months.

Runway, burn and cash flow

Runway is driven by burn rate. To model the timing of cash in and out in detail, use the cash flow calculator, and if you are considering debt, the business loan calculator shows the repayment impact.