Free calculator
Runway calculator
Runway is how many months a company can operate before its cash runs out: cash on hand divided by monthly net burn. Net burn is cash going out minus cash coming in. If burn is growing, runway is shorter than the simple division suggests, which is why this calculator lets you add monthly burn growth.
Cash reaches zero around October 2027 at today's burn.
$1,200,000 ÷ $100,000 a month.
Worked examples
| Inputs | Working | Result |
|---|---|---|
| $1,200,000 cash, $100,000 net burn, flat | $1,200,000 ÷ $100,000 = 12 | 12 months |
| $900,000 cash, $60,000 net burn, growing 5% a month | Burn runs $60,000, $63,000, $66,150 and so on. After 11 months $852,407 is spent, and the $47,593 left covers 0.46 of month 12, when burn is $102,620 | 11.5 months |
With burn growth, the calculator spends cash month by month, raising burn by the growth rate each month, and counts the part of the final month the remaining cash covers. A month is 30.4375 days when it turns months into a date. Growth is capped between minus 50% and 50% a month.
Sondola reads cash from Mercury and burn from QuickBooks Online or Xero, and recalculates runway each time the books change, with the period and source on the figure. See how it is calculated in the runway guide.
Questions
Should I use gross burn or net burn?
Net burn. Runway asks when cash reaches zero, and cash coming in from customers delays that. Gross burn is useful for a worst case where revenue stops.
Which cash counts?
Cash you can spend: bank balances and money market funds you can reach this month. Leave out money that is committed, restricted or owed to someone else.
How often should runway be recalculated?
Every month, from the month's actual burn. A runway figure goes stale as soon as spending or revenue changes.
Runway that updates itself.
Connect your bank and accounting once. Free for qualifying startups, read-only, and every figure shows its source.
Free for qualifying startups. Read-only.