When entrepreneurs start businesses, one of the last things they want to think about is running out of money. Whether the money is one’s own, that derived from friends and family, angel investors, or the bank, it has to be managed so that cash outflows are balanced by reserves and inflows. The term “Burn rate” is used commonly to describe  negative cash flow in a start-up. It indicates the speed of depletion of invested capital form shareholders. Once the cash reserves are used up, the company will either have to start making a profit, find additional funding, or close down. Venture Capitalists (VCs) are obviously very concerned about burn rates because they don’t want to see their investments wasted.

[Tom Tunguz, of Redpoint Ventures, in his blog, Ex Post Facto, writes the following:]

How does a VC think about your burn rate? First, it’s important to note that every company is different. Second, geography is an important factor. Third, pure consumer companies’ finances will differ dramatically from  e-commerce or SaaS companies. Given all those caveats, I’ve made a table of the rough figures that I expect to see in a company of various stages, immediately after financing.

When I make an investment, my aim is to fund the company to a milestone that enables the company to raise a subsequent round. Such a milestone tends to be achievable in 12 to 14 months. But a startup should raise 18 to 24 months’ capital to ensure some flexibility in case things don’t go according to plan.

A good rule of thumb in Silicon Valley is that every employee costs about $10k per month. By that estimate, a company of 20 people burns $200k for staff plus 25% for overhead, or $250k per month/$3M per year. This is on the richer side of burn rate calculations but given the rate of increase in engineering salaries recently, it may be closer to the norm.

For revenue generating companies, net burn (revenue – expenses) should be kept under $400k – $500k. A company burning more without the immediate prospect of revenue can be a concern because of how quickly these high burn rates reduce runway. Additionally, the company should aim to reach cash flow break even sometime after the Series B, before a Growth round. Again, every company is different, these guidelines are the mental model I’ve built of typical companies who have pitched us and worked with us.

Granted, Silicon Valley is more expensive than many other locales. Similarly, labor rates/salaries that drive the burn rate math are higher than in other regions. Even still, Tunguz makes a good point about the need to raise about 50% more than one expects will be required in terms of time to reach milestones. The “runway” referred to is the total amount of time before the venture crashes and burns due to lack of cash. As your company grows from solopreneur to employing 5+ people, these guidelines should come in handy to successfully manage the enterprise and its valuable cash.