Net burn and the efficiency ratio
Burn multiple measures how efficiently a company converts capital into growth. It is calculated as net monthly burn (total cash spent minus net new ARR gained) divided by net new ARR. A burn multiple of 1.0 means the company spent one dollar to add one dollar of annual recurring revenue. A burn multiple of 0.5 means it spent 50 cents per dollar of ARR added, a sign of efficient unit economics. A burn multiple of 2.0 means it spent two dollars per dollar of ARR added, suggesting either immature unit economics or aggressive growth spending that may not be sustainable. For a company with net new ARR of 100,000 dollars per month and net monthly burn of 80,000 dollars, burn multiple is 0.8, which is excellent. The same company with net burn of 200,000 dollars per month would have a burn multiple of 2.0, which would concern investors unless the growth rate justified temporary inefficiency.
Sustainable burn and runway
Burn multiple guides sustainability decisions. A venture-backed startup might accept a burn multiple above 1.0 in early stages to acquire customers at scale and build network effects. But as the company matures, burn multiple should shrink toward 1.0 or below, signaling that growth spending is yielding proportional returns. Burn multiple also informs runway calculations. A company with 10 million dollars in cash, monthly net burn of 500,000 dollars, and a burn multiple of 1.5 will burn through cash in 20 months unless revenue accelerates or burn decreases. Investor focus on burn multiple reflects a simple truth: revenue growth at any cost is growth into a brick wall unless unit economics eventually flip positive. Companies that keep burn multiple below 2.0 have more flexibility and more time to reach profitability.