✈️ Startup Runway Calculator
Runway is survival measured in months. Enter cash, revenue, and expenses to see exactly how long you have.
How Runway Math Works
Runway is how many months your cash lasts at the current burn rate. It is the most-watched number in early-stage startups — every fundraise, hiring plan, and pivot decision runs through it.
The Formulas
Runway = Cash on Hand ÷ Net Burn
Rules of thumb: raise when you have 6+ months left (fundraising takes 3–6 months); 18–24 months is the standard post-raise target; under 6 months is the danger zone. If revenue exceeds expenses you are profitable — runway is infinite, and the question flips to growth rate.
Worked Example
$500,000 cash, $40,000 monthly revenue, $90,000 expenses → net burn = $50,000/month → runway = 10 months. To reach a comfortable 18 months at this burn, the company needs $900,000 total — i.e., raise at least $400,000, and start now.
Extending Runway Without Raising
When runway drops below 12 months with no fundraise lined up, you have three levers: cut burn (cut once, cut deep — rolling layoffs destroy morale and still miss targets), grow revenue (annual prepay discounts convert future revenue into present cash; enterprise pilots become paid pilots), and bridge financing (extensions from existing investors, venture debt, or revenue-based financing). Know your "default alive" number: the growth rate at which current cash reaches profitability — if you're default alive, you negotiate from strength; if not, fundraising is existential and should start now. Fundraising itself takes 3–6 months, so begin at 9–12 months of runway, not 6. And model scenarios, not points: base, downside (revenue −30%), and hiring-plan cases — the downside case is the one that determines survival.
The two-runway rule: always know both your cash runway (this calculator) and your milestone runway — the months until you hit the traction target your next fundraise requires. If milestone runway exceeds cash runway, you must cut burn, accelerate growth, or raise immediately. Running out of cash with momentum is a fundable problem; running out without it is fatal.
Frequently Asked Questions (FAQs)
What is a good startup runway?
18–24 months after a fundraise is standard. Start raising with 6+ months remaining — fundraising typically takes 3–6 months and desperation kills valuations.
Gross burn vs net burn?
Gross burn = total monthly expenses. Net burn = expenses minus revenue — the actual cash drain. Runway always uses net burn.
What is the burn multiple?
Net burn ÷ net new ARR. Under 1× is efficient; 2–3× is typical for venture-backed growth; above 3× suggests unsustainable spending.
When should a startup cut costs?
When runway drops under 12 months with no fundraise in sight, or when the burn multiple stays above 3×. Cut once, cut deep — death by a thousand cuts destroys morale.
Does profitability mean infinite runway?
Yes — if revenue covers expenses, cash grows instead of shrinking. Then optimize for growth rate and margins rather than survival.
Last updated: September 2026