Burn rate is the amount of cash a company spends per period, usually per month, in excess of the cash it brings in. Among startup fundamentals it is the figure that tells founders and investors how fast the bank balance is shrinking, and therefore how long the company can operate before it needs new money, reaches profitability or must cut costs.
Burn rate is a cash measure, not an accounting profit measure. It looks at money actually leaving and entering the bank account, so it can differ substantially from the net loss on an income statement because of annual prepayments, deferred revenue, capitalized costs and the timing of supplier payments.
Gross burn and net burn
Founders distinguish two versions of the metric. Gross burn is total cash spent in a month on salaries, rent, cloud infrastructure, software, marketing and other operating costs. Net burn is gross burn minus cash received from customers and other operating sources in the same month. When people say burn rate without qualification, they almost always mean net burn.
| Measure | Calculation | What it reveals |
|---|---|---|
| Gross burn | Total monthly cash out | Size of the cost base and fixed commitments |
| Net burn | Cash out minus cash in | Actual monthly decline in the bank balance |
| Average net burn | Net burn averaged over three months | Trend without single-month distortions |
Both figures matter. Net burn determines runway today, but gross burn shows how much the company would lose if revenue suddenly stopped, for example after losing a large customer. A business with a low net burn and a very high gross burn is more exposed to revenue shocks than the headline number suggests.
Calculating burn rate and runway
The simplest calculation compares cash balances at the start and end of a period: net burn equals opening cash minus closing cash, divided by the number of months, after removing any new financing received. Runway then follows directly as cash on hand divided by average net burn.
Because a single month can be distorted by an annual software payment or a large customer prepaying a yearly contract, finance teams usually use a trailing three-month average. Forward-looking plans go further and model runway month by month, because hiring plans and revenue growth change the burn over time rather than holding it constant.
| Item | Value | Note |
|---|---|---|
| Cash on hand | 2,400,000 dollars | Bank balance after the last round |
| Monthly cash out | 260,000 dollars | Gross burn |
| Monthly cash in | 60,000 dollars | Customer receipts |
| Net burn | 200,000 dollars | 260,000 minus 60,000 |
| Runway | 12 months | 2,400,000 divided by 200,000 |
A common rule of thumb among early-stage investors is to raise enough to cover roughly 18 to 24 months of runway, because a new funding round typically takes several months from first meeting to cash in the bank. Starting a raise with less than about six months of runway leaves little negotiating power.
Burn rate compared with related startup metrics
Burn rate rarely stands alone. Investors read it together with growth and efficiency metrics to judge whether spending is buying durable progress or simply delaying problems.
| Metric | Question it answers | Link to burn rate |
|---|---|---|
| Runway | How many months of cash remain? | Cash divided by net burn |
| Burn multiple | How much cash is spent per dollar of new recurring revenue? | Net burn divided by net new ARR |
| Gross margin | How much revenue remains after delivery costs? | Higher margin lowers burn as revenue grows |
| Break-even point | When does cash in match cash out? | The month net burn reaches zero |
| Default alive | Will the company reach profitability before cash runs out? | Projects burn and growth together |
The burn multiple has become a popular efficiency lens for SaaS companies. A multiple near or below one is generally considered efficient, while values well above two suggest the company spends heavily for each unit of new recurring revenue, although acceptable levels vary with stage and market conditions.
Managing burn rate in practice
Burn is a deliberate choice, not an accident. A startup that has found product-market fit may rightly raise its burn to capture a market quickly, while a company still searching for fit should keep burn low so that it can afford several pivots. The decision table below summarizes typical responses.
| Situation | Typical burn stance | Reason |
|---|---|---|
| Pre-product-market fit | Low and flexible | Preserve time for experiments and pivots |
| Clear fit, efficient growth | Increase deliberately | Spending converts into durable revenue |
| Fundraising market weak | Extend runway | New capital may take longer or cost more |
| Under six months of runway | Cut or raise immediately | Options narrow quickly as cash declines |
Salaries are usually the largest component of gross burn in software startups, often well over half, so hiring plans dominate burn forecasts. Each new hire adds not only salary but taxes, benefits, equipment and software seats, and these commitments are slow to reverse.
Common mistakes with burn rate
The most frequent error is confusing net loss with cash burn. A SaaS company that collects annual contracts upfront may show a large accounting loss while its bank balance grows, and the reverse can happen when customers pay late. Founders should track burn from the bank statement and reconcile it with the accounts.
- Ignoring committed costs: signed leases and hiring offers raise future burn before they appear in current spending.
- Counting financing as income: loans and equity proceeds extend runway but do not reduce operating burn.
- Assuming flat burn: runway calculated on today’s burn overstates time left when spending is rising.
- Reacting too late: cost cuts take one to three months to show up in cash because of notice periods and contracts.
Explained without jargon
Burn rate is how quickly a young company uses up its money each month. If a startup has one million dollars in the bank and loses one hundred thousand a month, it has about ten months before the account is empty.
It works like the fuel gauge on a long drive with no gas station in sight. The number tells the driver how far the car can still go, and whether to slow down, find fuel or reach the destination first.
A typical use case
A software startup with fourteen employees closes a seed round and holds 3 million dollars. Its gross burn is about 210,000 dollars a month and customer receipts are 40,000 dollars, giving a net burn of 170,000 dollars and runway of roughly seventeen to eighteen months.
The founders plan to hire six engineers over the next quarter. Their model shows that the hires would raise net burn to about 280,000 dollars and cut runway to under eleven months unless revenue grows faster. They decide to hire four people now and tie the remaining two hires to reaching a monthly revenue milestone. This holds net burn near 220,000 dollars and keeps runway at roughly thirteen to fourteen months, giving the team enough time to show growth before starting its Series A process.