Definition
Burn rate measures how quickly a company is consuming cash, most commonly expressed as a monthly amount. It is particularly important for startups that are operating at a loss and relying on existing cash reserves or external financing to fund their operations.
There are two commonly used measures:
Gross burn: the total cash operating outflow during a period.
Net burn: the amount by which the company's cash balance decreases after accounting for cash received, such as revenue.
The distinction matters because a company can have substantial cash expenses while also generating significant cash revenue.
Gross burn vs. net burn
Gross burn
Gross burn measures the company's total cash operating outflows during a period.
For example, if a startup spends $300,000 in cash during a month on:
Salaries
Rent
Software
Marketing
Other operating expenses
its monthly gross burn is approximately $300,000.
Net burn
Net burn accounts for cash coming into the business.
If the same company receives $100,000 in cash from customers during that month:
Net burn = $300,000 − $100,000 = $200,000
The company's cash balance therefore decreases by approximately $200,000, assuming there are no other relevant cash movements.
How is burn rate calculated?
A simple monthly net-burn calculation is:
Net Burn = Cash Outflows − Cash Inflows
If a company spends $500,000 and receives $150,000 during a month:
Net Burn = $500,000 − $150,000 = $350,000
For a company with highly variable monthly cash flows, founders and investors may use an average burn rate over several months to reduce the effect of unusually high or low individual months.
Why does burn rate matter?
Burn rate helps a company understand how quickly it is consuming available cash.
It can inform decisions about:
Hiring
Marketing expenditure
Product development
Expansion
Fundraising
Cost reduction
Financial planning
For investors, burn rate can provide context for how efficiently a startup is deploying its capital and how much additional financing it may require.
Burn rate should not be assessed independently. A startup deliberately investing heavily to accelerate growth may have a higher burn rate than a slower-growing company.
Burn rate and runway
Burn rate is closely connected to runway, which estimates how long a company can continue operating before it runs out of available cash under a given set of assumptions.
A simplified calculation is:
Runway = Available Cash ÷ Monthly Net Burn
For example, if a company has:
$2 million in available cash
$200,000 monthly net burn
then:
$2 million ÷ $200,000 = 10 months of runway
This is only an estimate. Changes in revenue, expenditure, hiring, fundraising, and other cash movements can materially change the actual runway.
What causes burn rate to increase?
Common drivers include:
Hiring additional employees
Increased salaries
Higher marketing expenditure
Product development
Infrastructure costs
International expansion
Office or operational costs
Increased customer acquisition spending
Research and development
A higher burn rate is not automatically negative if the additional spending is generating sufficient progress or growth.
What causes burn rate to decrease?
A company can reduce burn by:
Slowing hiring
Reducing discretionary spending
Renegotiating supplier contracts
Reducing marketing expenditure
Improving operational efficiency
Increasing revenue
Reducing infrastructure costs
Delaying expansion
The appropriate response depends on why the company is burning cash and what business milestones it needs to achieve.
Burn rate and fundraising
Burn rate is particularly important when a startup relies on external financing.
A company needs to understand:
How much cash do we have? → How quickly are we using it? → What milestones can we reach before the cash runs out? → When should we raise additional capital?
Fundraising too late can leave a company with limited negotiating leverage.
Fundraising too early can mean raising capital before the company has reached milestones that could materially improve its financing position.
Burn rate therefore plays an important role in fundraising planning.
Burn rate vs. operating expenses
Burn rate and operating expenses are related but not identical.
Operating expenses are expenses incurred in running the business under the applicable accounting framework.
Burn rate generally focuses on the rate at which cash is being consumed.
Accounting expenses and cash movements do not always occur at the same time. Depreciation, accrued expenses, prepaid costs, working-capital movements, and other accounting treatments can cause operating expenses and cash outflows to differ.
For financial planning, founders should therefore distinguish between accounting expense and actual cash consumption.
Burn rate and growth
A startup may intentionally operate with a high burn rate while investing in growth.
The more useful question is often not:
"Is the burn rate high?"
but:
"What is the company achieving relative to the cash it is consuming?"
For example, investors may consider burn alongside:
Revenue growth
ARR growth
Customer acquisition
Gross margin
Retention
Unit economics
Product development
Market expansion
A company consuming substantial capital without corresponding progress may face a very different situation from one using capital efficiently to build a rapidly growing business.
Example
A startup begins the month with $3 million in cash.
During the month it:
Spends $450,000 on operations
Receives $150,000 from customers
Its approximate net burn is:
$450,000 − $150,000 = $300,000
If its monthly net burn remains $300,000 and there are no material changes in cash flows:
$3 million ÷ $300,000 = 10 months of runway
The founders can use this information when planning hiring, expenditure, and the timing of their next financing.
Common misconception
A high burn rate is always a sign of poor financial management.
No.
Burn rate needs to be considered in relation to growth, available capital, business model, and strategic objectives.
A startup may deliberately increase spending after raising a financing round to accelerate product development or market expansion.
The critical issue is whether the company has sufficient capital and a credible plan for converting that expenditure into meaningful business progress.
