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Cash flowJune 27, 2026 · 8 min read

What Is Burn Rate — and How to Calculate Yours in Under 5 Minutes

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You're not sure how many months of cash you have left. You know the number exists somewhere — in your bank account, your QuickBooks export, maybe a spreadsheet you built six months ago and haven't touched since. But you don't know it right now, confidently, without digging.

That's a burn rate problem. And it's one of the most fixable blind spots in small business finance.

What Burn Rate Actually Means

Burn rate is how much cash your business spends each month, net of revenue. It tells you how fast you're drawing down your cash reserves.

Two versions matter here:

Gross burn rate is your total monthly operating expenses before any revenue comes in — payroll, rent, software, contractors, supplies. Everything going out the door.

Net burn rate is what's left after you subtract revenue. Spending $40,000 a month and bringing in $35,000? Your net burn is $5,000 per month.

For most small businesses, net burn is the number that matters. It's the rate at which your cash balance is actually shrinking — or growing.

If your net burn is negative, you have a runway problem. If it's positive, you're building cash. Either way, you need to know the number.

Why Small Business Owners Ignore It

Not because they don't care. Because calculating it takes time they don't have.

A clean burn rate means pulling your bank statement, cross-referencing your P&L, separating one-time expenses from recurring ones, and deciding which revenue counts as reliable. That's 90 minutes in a spreadsheet, minimum, if your books are clean. Longer if they're not.

So most owners skip it. They check their bank balance instead, treat it as a proxy for financial health, and make decisions on gut feel. That works until it doesn't.

The bank balance tells you what you have right now. Burn rate tells you how long that lasts.

How to Calculate Burn Rate in Under 5 Minutes

You need two things: your total cash outflows for a recent month and your total revenue for that same period.

Step 1: Find your total monthly expenses

Pull your bank statement or your QuickBooks/Xero expense report for the last full month. Add up everything that went out — payroll, rent, subscriptions, vendor payments, loan payments, owner draws. Don't filter yet. Total it all.

That number is your gross burn rate.

Step 2: Find your total monthly revenue

Pull revenue for the same month. Use actual cash received, not invoiced — you want what actually hit your account.

Step 3: Subtract

Net burn rate = Total expenses minus total revenue

Spent $52,000 and collected $47,000? Your net burn is $5,000 per month.

Step 4: Calculate your runway

Runway = Current cash balance divided by net burn rate

$60,000 in the bank, burning $5,000 a month — that's 12 months of runway.

That's the number. It takes less than five minutes if your data is accessible.

What a Healthy Burn Rate Looks Like

There's no single right number. It depends on your stage, your industry, and whether you're growing intentionally or bleeding quietly.

Positive net burn (spending more than you earn): Acceptable if you're investing in growth and have enough runway to reach profitability. Dangerous if you don't know your runway — or it's under six months.

Zero net burn (breaking even): You're not building cash, but you're not losing it. Fine for a stable business. A problem if you have no cushion for a slow month or an unexpected expense.

Negative net burn (earning more than you spend): You're building cash. This is where you want to be. The question becomes: how much cushion do you actually have, and what should you do with it?

Most small businesses should carry at least three months of runway as a minimum cushion. Six is better. Below three months, burn rate isn't just a metric to monitor — it's the most important number in your business right now.

For a broader look at the metrics that belong alongside burn rate, the five financial metrics every small business owner should see every morning in 2026 covers exactly that.

The Three Mistakes Owners Make with Burn Rate

Using the bank balance instead

Your bank balance is a snapshot. Burn rate is a rate of change. A $100,000 balance looks healthy until you realize you're burning $30,000 a month and have a $40,000 payroll due in two weeks.

Calculating it once and forgetting it

Burn rate changes every month. A new hire, a slow quarter, a big client churning — any of these shifts your burn meaningfully. Calculate it monthly, not annually.

Treating all expenses as equal

Some expenses are fixed and recurring. Others are one-time or variable. Your fixed burn — rent, payroll, subscriptions — is your floor. What you owe regardless of revenue. Your variable burn is where you have flexibility. When you're analyzing burn, separating the two matters.

How Burn Rate Connects to Bigger Decisions

Burn rate isn't just a health metric. It's a decision-making input.

Thinking about hiring? A new employee at $5,000 per month in total cost raises your gross burn by $5,000. If your net burn is already $3,000, that hire pushes you to $8,000 per month. At $60,000 in the bank, your runway drops from 20 months to 7.5. That's the conversation you need to have before you make the offer.

Heading into a slow season? If Q1 typically runs 30% below your average monthly revenue, you can model what that does to your burn and runway before it happens — and decide whether to cut variable expenses, draw down savings, or hold a line of credit in reserve.

This is where burn rate stops being a backward-looking report and starts being a planning tool.

For a look at how burn rate fits into a complete picture of cash health, the best cash flow tracker for small business owners in 2026 walks through what to look for in a tool that keeps these numbers current.

Keeping Burn Rate Current Without a Spreadsheet

The calculation is simple. Keeping it current is the hard part.

Most owners do this manually — pull the data, run the math, update a spreadsheet — then let it go stale for weeks. By the time they check it again, the number is three months old and two hires behind.

CFO X is built to solve exactly this. The desktop shows your burn rate, cash position, and runway as live widgets, updated as your data changes. Drag in a bank statement or expense export and the numbers recalculate. Ask a plain-language question — "what's my net burn this month?" or "how does adding one employee change my runway?" — and CFO X answers without a pivot table or a formula.

The scenario builder lets you move a hiring slider, adjust an assumed revenue figure, or model a slow month and see the impact on your burn and runway in a side-by-side view before you commit to anything.

CFO X also remembers your business across sessions. You don't re-explain your structure, your payroll, or your seasonality every time you open it. It already knows.

Learn more at cfo-x.ai.

FAQs

What is burn rate for a small business? Burn rate is the amount of cash your business spends each month. Net burn rate subtracts your monthly revenue from your expenses, showing whether your cash balance is growing or shrinking — and by how much.

How do I calculate my burn rate? Add up all cash outflows for a recent month — payroll, rent, subscriptions, vendor payments. That's your gross burn. Subtract your monthly revenue to get your net burn. Divide your current cash balance by your net burn to find your runway in months.

What is a good burn rate for a small business? There's no universal answer. The key question is whether your runway gives you enough time to reach or maintain profitability. Most small businesses should carry at least three to six months of runway as a cushion. Below three months, reducing burn becomes the priority.

How often should I calculate burn rate? Monthly, at minimum. Burn rate shifts with every hire, price change, or slow season. Calculate it once a year and the number is almost certainly wrong by the time you use it.

What's the difference between gross burn and net burn? Gross burn is your total monthly expenses before revenue. Net burn subtracts revenue from expenses. Net burn is the more useful number for most small business owners because it reflects the actual rate at which your cash balance is changing.

Can burn rate be positive? Yes. If your revenue exceeds your expenses, your net burn is negative in the traditional sense — meaning you're generating cash, not consuming it. Either way, the math is the same: track the direction and the rate.

How does burn rate relate to cash runway? Runway is your cash balance divided by your net burn rate. $90,000 in the bank, $10,000 monthly net burn — that's nine months of runway. Burn rate is the input. Runway is the output that tells you how long you can operate before you need more revenue, lower expenses, or outside capital.

The Bottom Line

Burn rate is not a complicated concept. It's a division problem. The hard part is having clean, current data to feed it — and the discipline to check it every month, not just when something feels wrong.

Know your gross burn. Know your net burn. Know your runway. Those three numbers tell you more about the financial health of your business than any report you'll get at the end of the quarter.