Burn rate

A startup spending faster than it earns is, in effect, burning money. How fast it burns, the burn rate, is a matter of life and death.

Burn rate is the rate at which a company, typically a startup not yet profitable, spends its cash reserves, usually measured per month. It is one of the most closely watched figures in a young venture, because a company that burns through its cash before reaching profitability or raising more dies, however promising it once looked.

Spending faster than earning

Most startups spend more than they earn for a period, investing in growth before they are profitable, and the burn rate measures how fast they are consuming the cash they have. It is the speed at which the reserves are being depleted, the monthly gap between what the company spends and what it brings in. For a venture living on a finite pool of cash, raised from investors or earned and reinvested, the burn rate determines how long that pool will last, and so how long the company has to reach profitability or raise more before it runs dry.

Burn rate and runway

Burn rate is inseparable from runway, the length of time the company can survive at its current burn before the cash runs out. Divide the cash reserves by the monthly burn rate, and you get the runway, the number of months left. This makes burn rate a matter of survival: a high burn rate shortens the runway and the time available to reach a sustainable position or secure more funding, while a lower burn rate extends it. Managing the burn rate is managing the time the company has left, and miscalculating it, running out of runway unexpectedly, is a common and fatal startup failure.

The tension over how fast to burn

How fast to burn is a genuine strategic tension. Burning faster, spending aggressively, can buy faster growth, winning a market, building a product, or reaching scale more quickly, which may be essential where speed is decisive. But it shortens the runway and raises the risk of running out before the bet pays off. Burning slower conserves cash and extends the runway, buying time and reducing risk, but may cede ground to faster-moving rivals. The right burn rate depends on the opportunity, the funding available, and the confidence that the spending will pay off in time, a judgement that can make or break a venture.

Burn rate is the speed at which a young company consumes its cash, the figure that, against its reserves, determines its runway and so its survival. Its management is a matter of life and death for a startup, since burning too fast risks running out before reaching profitability or new funding, while burning too slowly may forfeit the growth that speed could win, making the calibration of how fast to spend one of the most consequential and unforgiving judgements a founder faces.