Calculate your startup's cash runway, zero cash date, and break-even timeline. Free tool with revenue modeling, scenario comparison, fundraising planning, and Default Alive analysis.
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Cash runway is the most critical metric for startup survival. It tells you how many months your startup can operate before running out of cash. Our Runway Calculator helps you project your zero cash date, plan fundraising timing, and understand if you're 'Default Alive'—Paul Graham's framework for determining if you'll become profitable before running out of money.
Runway is the number of months a startup can operate before running out of cash, calculated by dividing current cash balance by monthly burn rate. For startups with revenue, net burn (expenses minus revenue) provides a more accurate runway projection. Understanding your runway is essential for fundraising timing, hiring decisions, and strategic planning.
Runway Formula
Runway (months) = Cash Balance ÷ Monthly Burn Rate\n\nWith Revenue: Runway = Cash Balance ÷ (Monthly Expenses - Monthly Revenue)Start fundraising when you have 9-12 months runway. Fundraising takes 3-6 months, and you need buffer for delays. Never start with less than 6 months—desperation fundraising leads to poor terms.
Know exactly when cash runs out so you can make informed spending decisions. Cut costs, defer purchases, or accelerate revenue before it's too late.
Runway is a standard metric in board reports. Investors expect accurate runway projections and early warning when runway gets short.
Runway affects every decision: hiring, marketing spend, product roadmap. More runway = more freedom to invest in growth.
Avoid running out of cash unexpectedly. With accurate runway projections, you can plan for worst-case scenarios and take action early.
Determine if your revenue growth trajectory will make you profitable before cash runs out. Default Alive startups have better negotiating position.
Include runway in every board deck. Track trends over time and set targets for runway extension through growth or efficiency.
Calculate runway 6-9 months before you need to start raising. Determine your raise amount based on target runway (typically 18-24 months post-raise).
Model different spending scenarios to see runway impact. Balance growth investment against runway preservation.
Before extending headcount, calculate runway impact. Each hire accelerates burn—ensure you have runway to see ROI.
When changing business model or market, recalculate runway with new assumptions. Pivots often require more runway.
In economic downturns or funding droughts, model aggressive cost-cutting scenarios to extend runway and survive.
Runway is the number of months a startup can operate before running out of cash, calculated by dividing current cash balance by monthly burn rate. For example, $500K cash with $50K monthly burn = 10 months runway. It's the most critical metric for startup survival and fundraising planning.
Basic formula: Runway = Cash Balance ÷ Monthly Burn Rate. For more accuracy, account for revenue: Runway = Cash ÷ (Monthly Expenses - Monthly Revenue). For startups with growing revenue, use projections: model each month's cash, expenses, and revenue until cash reaches zero.
Best practice is 12-18 months minimum. Pre-seed/Seed: 12-18 months; Series A: 18-24 months; Series B+: 24+ months. Always maintain enough runway to raise your next round (6-9 months for fundraising process) plus buffer for unexpected delays.
15-18 months is considered healthy for most startups. Less than 6 months is critical and requires immediate action. 9-12 months is acceptable but fundraising should begin. Over 24 months may indicate under-deployment of capital unless maintaining strategic reserves.
Burn rate is how much cash you spend per month (a rate). Runway is how long your cash will last (a duration). They're related: Runway = Cash ÷ Burn Rate. Burn rate is the speed; runway is the distance you can travel at that speed.
Start fundraising when you have 9-12 months of runway remaining. Fundraising typically takes 3-6 months, and you need buffer for delays. Never start with less than 6 months runway—desperation fundraising leads to poor terms.
When runway reaches zero, the startup can no longer meet payroll, pay vendors, or operate. Options at this point: emergency bridge funding (often at bad terms), acqui-hire, shutdown, or personal loans from founders. Most startups that reach zero cash fail to recover.
Strategies: (1) Cut non-essential expenses, (2) Reduce headcount or salaries, (3) Renegotiate vendor contracts, (4) Accelerate revenue or collections, (5) Defer large purchases, (6) Convert fixed costs to variable, (7) Bridge loans from existing investors, (8) Revenue-based financing.
Concept from Paul Graham: 'Default Alive' means your revenue growth trajectory will make you profitable before cash runs out. 'Default Dead' means you'll run out of cash before becoming profitable. Default alive startups have better negotiating position and lower risk.
Rule of thumb: Start fundraising at 9-12 months runway. Announce/begin outreach at 9 months, aim to close by 6 months remaining. This gives 3-6 months for the process plus buffer. Exception: if metrics are exceptional, you can raise from strength at any runway.
12 months is the minimum acceptable runway for most startups. It's enough to operate but leaves little margin for fundraising delays or pivots. For comfort, target 15-18 months. With only 12 months, begin fundraising preparations immediately.
Revenue reduces your net burn rate, extending runway. With $100K monthly expenses and $40K revenue, net burn is $60K instead of $100K—extending runway by 67%. Growing revenue can dramatically extend runway or make you 'default alive' (profitable before cash runs out).
Zero cash date is the specific day your startup will run out of money at current burn rate. It's calculated by projecting monthly cash balances until reaching zero. This is the hard deadline by which you must raise, cut costs, or generate revenue.
Calculate runway monthly at minimum, ideally weekly for early-stage startups. Update whenever: (1) major expense changes, (2) revenue shifts, (3) fundraise closes, (4) hiring/firing occurs. Include runway in monthly board reports and team updates.
Infinite runway means your revenue exceeds expenses—you're profitable and don't need external funding to survive. Some call this 'ramen profitable' at low scale or 'default alive' when approaching profitability. Infinite runway gives maximum strategic flexibility.