SeedBattle

Startup runway calculator

Runway is how long your cash lasts at your current burn — and, with it, your zero-cash date. It is the single most important number for timing a fundraise.

Runway

$
$
$
Net monthly burn
$60.0K
Runway
16.7 months
Zero-cash date
Feb 2028

What is startup runway?

Runway is the number of months a company can keep operating before it runs out of cash, assuming nothing changes. It is a function of how much money you have and how fast you’re spending it net of revenue.

How to calculate runway

Net monthly burn = Monthly costs − Monthly revenue Runway (months) = Cash in bank ÷ Net monthly burn

The key is net burn. A company spending $100k a month but bringing in $30k of revenue is only burning a net $70k — so revenue growth directly lengthens runway.

Gross burn vs net burn

  • Gross burn — total cash going out the door each month.
  • Net burn — gross burn minus revenue; this is what runway is based on.

A worked example

With $1,000,000 in the bank, $80,000 in monthly costs and $20,000in monthly revenue, net burn is $60,000 and runway is about 16.7 months — putting the zero-cash date roughly a year and a half out.

How much runway should you keep?

Most founders aim to raise their next round with 6–9 months of runway left, and to end a raise with 18–24 months. Running the tank too low removes your leverage and your options.

Frequently asked questions

How do you calculate startup runway?

Runway = cash in the bank ÷ net monthly burn, where net burn = monthly costs − monthly revenue. If you have $1,000,000 in the bank and burn a net $80,000 a month, you have 12.5 months of runway. If revenue exceeds costs you are profitable and runway is effectively unlimited.

What is the difference between gross and net burn?

Gross burn is your total monthly cash outflow (all costs). Net burn subtracts revenue: net burn = costs − revenue. Runway is based on net burn, because incoming revenue extends how long your cash lasts.

How much runway should a startup have?

A common guideline is 18–24 months of runway after a raise, and most founders start their next fundraise with 6–9 months of runway remaining — raising takes time, and negotiating from a position of dwindling cash weakens your hand.

What is a zero-cash date?

The zero-cash date (or "out-of-cash date") is the calendar month your bank balance is projected to hit zero at the current net burn. It is one of the most important numbers for any founder to know and track.

How can I extend my runway?

Increase revenue, reduce costs, or raise more capital. Because runway depends on net burn, even modest revenue growth or cost cuts can add several months — and every extra month buys time to hit the milestones that unlock your next round.

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