Burn rate refers to the speed at which a company depletes its cash reserves to cover operating expenses before achieving profitability or positive cash flow. Most commonly expressed as a monthly figure, burn rate tells investors how much runway a startup has before it needs additional financing or must reach break-even.
Investors calculate burn rate by subtracting a company's cash balance at month-end from its starting balance. A startup with $2 million in the bank that ends the month with $1.8 million has a monthly burn rate of $200,000. This metric becomes critical during due diligence, as it directly impacts how long your investment will sustain operations and when the company might need its next funding round.
Why It Matters
Burn rate determines survival timeline. A company burning $150,000 monthly with $900,000 in the bank has six months of runway—barely enough time to hit key milestones and raise another round. Angel investors use this metric to assess management's capital efficiency and strategic thinking. High burn rates aren't automatically bad if they're driving proportional growth, but unsustainable spending patterns signal poor financial discipline. Smart investors compare burn rate against revenue growth, customer acquisition costs, and progress toward product-market fit to evaluate whether the company is spending wisely or simply burning through capital.
Example
Consider two SaaS startups, each with $1.5 million in seed funding. Company A burns $250,000 monthly on a large sales team and expensive office space, giving it six months of runway but only adding 20 new customers per month. Company B burns $100,000 monthly with a lean remote team, securing 15 months of runway while adding 25 customers monthly. Despite slower initial hiring, Company B demonstrates better unit economics and has time to iterate toward profitability. An angel investor evaluating both companies would likely favor Company B's disciplined approach, which provides flexibility to adapt strategy without immediately needing dilutive financing.