Runway calculator

Burn rate and runway

Net burn is what you spend each month minus what comes in. Runway is how many months your cash covers that gap:

net burn = monthly expenses - monthly revenue

runway = cash / net burn

With $30,000 in the bank, $4,000 of costs and $1,500 of revenue, net burn is $2,500 a month and runway is 30,000 / 2,500 = 12 months, if nothing changes. The runway glossary entry explains gross and net burn in more detail.

Runway with growth: default alive or default dead

Revenue rarely stays flat, so the calculator also runs month by month with your revenue growing at the rate you enter. Each month it takes the gap out of your cash and grows revenue; if revenue reaches your costs before the cash is gone, you never run out.

In the example, growing revenue 10% a month takes $1,500 past $4,000 in month 11, while there is still cash left, so the runway with growth reads "Never runs out". Paul Graham calls this being default alive: on your current path you reach profitability before the money ends (Default Alive or Default Dead?). Try a lower growth rate in the same example and watch the answer turn into a number of months, which is the point of looking at both.

What to put in

• Cash: what is in the bank today and available to the business.
• Expenses: everything you pay each month: hosting, tools, contractors, fees, and your own salary if you take one. If you live on savings, count your living costs too, since that is the real runway.
• Revenue: MRR for a subscription product, or your average monthly sales for one-time purchases.
• Growth: your recent month on month revenue growth. Use a cautious number; the ARR calculator and churn calculator help you find one.

The calculator stops counting at ten years and treats every month alike, so it ignores yearly bills and seasonal sales. It is a direction, not an accountant.

Make the revenue side visible

Runway is the number founders keep private; revenue is the one worth sharing. If you build in public, a page with verified revenue shows it straight from Stripe, Paddle, Lemon Squeezy, Gumroad, RevenueCat or Shopify, so the growth you are counting on is there for anyone to see. Running alone? See makerhandle for solo founders and what it means to be bootstrapped.