Burn rate: what it tells you that your P&L doesn't
Gross burn, net burn, and what each one signals about how long you can operate at your current shape — for businesses that aren't venture-backed.
Burn rate arrived in general business vocabulary through venture-backed startups, where it means how fast you're spending investors' money. That's made a lot of profitable owner-operated businesses assume it doesn't apply to them.
It does. Burn is simply the rate at which cash leaves your business, and knowing it — separately from your profit — tells you things the P&L structurally cannot.
Gross versus net
Gross burn is total cash out in a month. Payroll, rent, suppliers, debt service, tax, everything.
Net burn is gross burn minus cash in. If you collected $180,000 and spent $200,000, net burn is $20,000. If you collected $220,000, you had positive net cash flow of $20,000 — sometimes called negative burn, which is a clumsy phrase for a good outcome.
Both matter, and they answer different questions.
Net burn tells you how long you last. Gross burn tells you how exposed you are if revenue stops.
A business collecting $500,000 and spending $490,000 has a comfortable net burn and an alarming gross one — because if a major customer leaves, half a million dollars of monthly obligation doesn't move for months.
Why profit doesn't tell you this
Profit and burn diverge for reasons that are entirely normal:
- Timing. You recognised revenue in March and will collect in May.
- Non-cash costs. Depreciation reduces profit without touching the bank.
- Debt principal. Repayments leave cash but don't appear on the P&L.
- Capital purchases. A $60,000 van is cash today and a small monthly expense for years.
- Tax. Accrued monthly, paid in lumps.
This is why a profitable month can still lower your bank balance, and why owners are surprised by it more often than they should be.
The number to track
For a non-venture business, the most useful version is committed gross burn: the portion of monthly cash out you cannot change inside ninety days. Payroll, leases, debt service, insurance, contracted suppliers.
That figure defines your floor. Divide available cash by it and you get the honest answer to "how long could we survive if revenue went to zero" — the number that should sit behind every large commitment.
It also tells you how much operating leverage you have. A business where 80% of burn is committed has very little room to respond to a bad quarter. One at 50% has options.
Reading the trend
The level matters less than the direction. Three patterns worth catching early:
- Burn rising faster than revenue. Growth that consumes more than it returns. Fine deliberately, dangerous by accident.
- Committed share creeping up. Each new salary, lease or subscription converts flexible cost into fixed. It happens one small decision at a time and is only visible when tracked.
- Net burn stable, gross burn rising. You're getting bigger without getting safer. More revenue funding more obligation, same cushion.
One metric to leave alone
Burn multiple — net burn divided by net new ARR — is a genuinely useful venture metric and almost meaningless for an owner-operated business. It's designed to assess capital efficiency for an investor deciding whether to fund more growth. If nobody is funding your growth but you, it answers a question you aren't asking.
Track gross, net, and the committed portion. The burn rate calculator will do the arithmetic in a couple of minutes.