How long until the money runs out? Enter your cash and burn rate, add revenue growth if you have it, and get your months of runway and zero-cash date.
6-12 months is workable but tight. Most investors want to see 12-18 months of runway after a raise.
Assumes flat expenses and compounding revenue growth. Real runway moves with hiring, churn, and seasonality, which is what a month-by-month model captures.
See how hiring plans, growth scenarios, and churn change your zero-cash date.
Model your full financialsThe textbook version is one division: cash on hand divided by net burn rate. Net burn is monthly expenses minus monthly revenue; if you are pre-revenue, net burn equals gross burn and the math is even simpler. The catch is that the one-line formula assumes nothing changes, and for a startup with growing revenue that assumption is wrong in your favor. This calculator projects your balance month by month, compounding revenue growth, so a company with $120,000 in cash, $15,000 in expenses, and $3,000 of revenue growing 5% monthly gets credit for that growth instead of a flat 10-month answer.
Two deeper dives if you want the full mechanics: our burn rate guide covers gross versus net burn and how to measure it from your bank statements, and the runway metric page covers the benchmarks investors use.
The standard advice is 12-18 months of runway after a raise, and it holds up because of how long everything takes. A seed round takes 3-6 months of active fundraising. Finding product-market fit usually takes longer than planned. Stack those and a 9-month runway leaves almost no room for a single missed assumption. That said, more runway is not free: it comes from raising more (dilution) or spending less (slower growth), so treat 12-18 months as a floor to defend, not a target to maximize.
One caveat on the growth input: 5-10% month-over-month revenue growth is a solid early-stage pace, and it is tempting to type in 20% and watch the zero-cash date vanish. Be pessimistic here. Our guide to startup burn rate walks through how founders systematically underestimate burn and overestimate growth, and what that does to real runway.
A runway number is a snapshot; a plan is a model. Real burn is lumpy: a hire adds $6,000-12,000 a month, churn eats into the revenue line, ad spend scales with growth targets. A month-by-month financial model captures all of it and shows your zero-cash date under base, optimistic, and pessimistic scenarios, so you know which levers actually move the date. Start with the break even calculator to see the revenue level that ends the burn entirely, or estimate your launch budget first with the startup cost calculator.
Project your burn, runway, and zero-cash date month by month, with hiring, churn, and three scenarios built on real benchmarks.
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