Find out exactly how many months your startup can survive before the cash runs out. Enter your current cash, monthly revenue, growth rate, and burn rate line items — and see your runway update in real time with optimistic, base, and pessimistic scenarios.
Pro tip: Most founders underestimate burn by 15–20%. Be honest with every line item and add a “Misc” buffer. If your runway is under 6 months, it is time to cut costs or start fundraising immediately — fundraising itself takes 3–6 months.
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Pessimistic
Add planned hires to see how they affect your runway. Each hire adds to burn starting in the specified month.
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Based on your runway, see when to start fundraising, how much to raise, and the implied valuation at common dilution levels.
How to Use the Startup Runway Calculator
Start with your cash on hand — the total liquid capital your startup has right now. Then enter your monthly revenue (set it to zero if you are pre-revenue) and adjust the revenue growth rate slider to reflect your expected month-over-month growth. Finally, fill in each burn rate line item with your actual monthly costs. The calculator instantly shows how many months you have before the money runs out, plus optimistic and pessimistic scenarios so you can plan for different outcomes.
What Is Startup Runway?
Runway is the number of months a startup can continue operating before it runs out of cash, assuming current spending and revenue trends continue. It is the single most important survival metric for any early-stage company. A startup with 18 months of runway has breathing room to iterate, find product-market fit, and raise the next round. A startup with 3 months of runway is in crisis mode. Knowing your exact runway lets you make informed decisions about hiring, spending, and when to start fundraising.
Understanding Burn Rate: Gross vs. Net
Gross burn is your total monthly spending — salaries, rent, software, marketing, everything that goes out the door. Net burn is gross burn minus revenue — the actual cash you lose each month. If you spend $50,000 per month and bring in $20,000 in revenue, your gross burn is $50,000 and your net burn is $30,000. This calculator uses net burn to compute runway because revenue offsets your spending and extends your lifeline.
Default Alive vs. Default Dead
Paul Graham coined these terms to describe whether a startup will reach profitability before running out of money. If your current revenue growth trajectory will make revenue exceed expenses before cash hits zero, you are default alive. If not, you are default dead — meaning you will need to either cut costs, grow faster, or raise money to survive. This calculator shows you exactly which category you fall into by projecting revenue growth against burn.
When to Start Fundraising
The general rule is to start fundraising when you have 6 to 9 months of runway remaining. Fundraising typically takes 3 to 6 months from first meeting to wire transfer, and you never want to negotiate from a position of desperation. If your runway is under 6 months and you have not started the process, you are already behind. The fundraising timeline advisor (available to subscribers) calculates the ideal start date and target raise amount based on your current burn rate and growth trajectory.
How Revenue Growth Extends Runway
Even modest revenue growth dramatically extends runway. A startup burning $40,000 per month with $200,000 in cash has 5 months of runway at zero growth. But with $10,000 in monthly revenue growing at 15% month-over-month, revenue catches up to expenses before the cash runs out, making the company sustainable. The growth rate slider lets you model exactly how different growth scenarios change your outcome from dead to alive.
Extending Your Runway
There are only three ways to extend runway: increase revenue, decrease costs, or raise more capital. On the cost side, the biggest lever is usually headcount — salaries and benefits often account for 60–80% of a startup's burn. Before cutting headcount, look at non-essential spending: unused software subscriptions, excessive marketing spend with unclear ROI, and office space you do not need. Every dollar saved per month is another month of runway when multiplied across your remaining cash.
Lifestyle Creep in Startups
After a fundraise, many startups dramatically increase spending — nicer offices, premium tools, rapid hiring — without a proportional increase in revenue. This “lifestyle creep” burns through the new capital faster than expected and shortens runway. The most disciplined founders treat every dollar as precious regardless of how much is in the bank. Use the burn rate line items to audit each category and ask whether each expense directly contributes to growth or survival.
Looking for related tools? Try our Break-Even Calculator to find the sales volume needed to cover your costs, or our Margin Calculator to calculate profit margins and markups. Explore all Freelance & Business tools.