Startup Runway Calculator: Are You Default Alive?
Free startup runway calculator. Enter cash, revenue, expenses, and growth to see your runway, burn rate, and whether you are default alive or default dead.
Your finances
What is runway?
Runway is how many months your company can keep operating before the bank account hits zero. It's the most important number for any startup that isn't profitable yet, because it sets the deadline for everything else.
Simple runway
Runway (months) = cash in the bank ÷ monthly net burn
Net burn is monthly expenses minus monthly revenue. With $60,000 in the bank, $9,000 of expenses, and $3,000 of revenue, net burn is $6,000 and simple runway is 10 months.
Default alive vs. default dead
Simple runway assumes revenue never grows, which is pessimistic for a growing startup. Paul Graham's essay Default Alive or Default Dead? asks a better question:
Assuming expenses stay constant and revenue keeps growing at its recent rate, will you reach profitability before the money runs out?
- Default alive: revenue overtakes expenses before cash hits zero. You'll survive without raising money.
- Default dead: you'll run out of cash first. You need to raise, cut costs, or grow faster, and the earlier you know, the more options you have.
This calculator simulates your finances month by month: revenue compounds at your growth rate, expenses grow at theirs, and the cash balance updates each month. The chart shows the result.
How to extend your runway
- Cut the burn you don't feel. Audit subscriptions, unused seats, and over-provisioned infrastructure. Small cuts compound over a year of runway.
- Sell annual plans. Twelve months of cash upfront, often at a 15–20% discount, can add months of runway in one go.
- Raise prices. Most early products are underpriced, and a price increase on new customers costs little. See how to price your SaaS.
- Hit ramen profitability. Revenue that covers the founders' basic living costs takes the time pressure off. Find out how many customers you need.
- Raise before you need to. Fundraising takes 3–6 months. Start when you have at least 9 months of runway left.
Common mistakes
- Using gross burn instead of net burn. Revenue counts!
- Forgetting annual costs. Insurance, legal, and annual software renewals show up all at once.
- Assuming growth stays constant. Test a pessimistic scenario with half your current growth rate.
Frequently asked questions
How do I calculate startup runway?
Runway = cash in the bank ÷ monthly net burn, where net burn is monthly expenses minus monthly revenue. $120,000 of cash with a $10,000 net burn gives 12 months of runway.
What does default alive mean?
A startup is default alive if, at its current revenue growth rate and constant expenses, it becomes profitable before running out of money. The term comes from a Paul Graham essay.
What is the difference between gross burn and net burn?
Gross burn is total monthly spending. Net burn is spending minus revenue, the amount your cash balance actually falls each month. Runway uses net burn.
How much runway should a startup have?
A common rule is 18–24 months after a fundraise, and to start raising again with at least 9 months left, since fundraising often takes 3–6 months.