Finance operations · August 15, 2026

Cash burn rate: the formula, net vs gross burn, and why your number is already three weeks old

Cash burn rate is how fast you spend your cash reserves, stated per month. Gross burn is everything going out. Net burn is that minus what came in, and net burn divided into your bank balance gives you runway. The arithmetic takes a minute. The problem is that almost everyone computes it from a closed month, which means the number telling you your burn changed arrives two to three weeks after the money already left.

That lag is not a rounding error. On a 12-month runway, finding out three weeks late that burn stepped up by 15 percent costs you real optionality, because the decisions that respond to it (a hiring pause, a renewal you do not sign, a contract you renegotiate) all take weeks more to take effect. So this piece covers the formulas properly, and then covers the part most burn rate guides skip: what to watch inside the month, while you can still act.

The two formulas, and which one matters

There are two burn figures and people mix them up constantly, usually in the same conversation.

Gross burn is total cash operating expenses for the month. Payroll, payroll taxes, contractors, software, rent, hosting, marketing, professional fees, everything that leaves the account to run the business. Revenue does not enter into it.

Net burn is gross burn minus the cash you actually collected that month. Note the word collected. Burn is a cash measure, so it counts money received, not invoices issued. If you billed $80,000 and collected $30,000, the $30,000 is what reduces your burn.

Worked through: a company spending $150,000 a month that collected $50,000 has a gross burn of $150,000 and a net burn of $100,000. Holding $1.2 million in the bank, runway is $1.2 million divided by $100,000, so 12 months.

If you are profitable on a cash basis, net burn is negative and runway is not a meaningful number. That is the goal, and it is worth saying plainly because a lot of burn content assumes every reader is pre-revenue. Plenty of businesses with real revenue still track burn closely, because a bad quarter turns a positive number negative faster than a hiring plan can be unwound.

The shortcut that gives the wrong answer

Here is how most teams actually compute burn, because it takes ten seconds: take last month's closing bank balance, subtract this month's, and call the difference the burn.

It is a reasonable approximation about half the time and badly misleading the rest, because a bank balance moves for reasons that have nothing to do with your operating spend. Four things distort it routinely.

Annual prepayments. Your insurance renewal, your annual software contracts and your compliance audit do not spread themselves evenly. A $60,000 annual renewal paid in March makes March look catastrophic and the following eleven months look better than they are. The cash left in March, so it is genuinely cash out, but attributing it entirely to March's run rate is wrong.

Payroll calendar collisions. On a biweekly cycle, two months a year contain three payrolls instead of two. That is a 50 percent increase in your largest single cost line, caused entirely by the calendar. If those months are the ones you happen to average, your burn is overstated by a wide margin.

Collection timing. A large customer paying on the 2nd rather than the 30th shifts the same money across a month boundary. Nothing about the business changed, but two consecutive burn figures both move, one down and one up. This is the single most common cause of a burn number that panics a board with no underlying story.

Financing inflows. A tranche of a raise, a loan drawdown, a tax refund or an R&D credit all increase the bank balance without being revenue. Include them and your burn looks like it improved in a month where operations did not change at all.

The fix is not complicated: compute burn from operating cash flows, exclude financing entirely, and average the last three months rather than reading a single one. Below is the same company under both methods, and the gap between the two columns is the reason this matters.

Look at March. On the balance-delta method the company appears to have generated cash, and if that figure reaches a board deck without a footnote, somebody will draw a conclusion from it. The operating view says the cost base did not move at all. Same company, same quarter, two stories.

What is a good burn rate for a startup?

There is no universal dollar figure, because it depends entirely on stage, sector and how fast you are growing. The question is better asked as runway, and there the guidance is fairly consistent. Most current advice puts the target at 18 to 24 months of net-burn runway after a raise, having drifted up from the older 12-to-18-month rule. The reasoning is mechanical rather than philosophical: a full fundraise from first meeting to money in the bank commonly takes three to six months, so beginning that process with six months of runway means negotiating from a position where you cannot walk away.

The second test is efficiency rather than duration. Burn should be growing more slowly than revenue. If burn is up 40 percent year over year and revenue is up 20 percent, the direction is wrong regardless of how much cash is in the bank, and no amount of runway fixes a ratio moving the wrong way.

Both tests share a weakness worth naming: they are computed on closed periods. They tell you where you have been. Neither tells you that this month is running 12 percent hot while you still have two weeks to do something about it.

Watching burn inside the month

This is the part that changes outcomes. Burn is a lagging indicator by construction, but the spending that produces it is happening continuously and is visible as it happens. Four leading indicators cover most of what actually moves the number.

Card and account spend against a month-to-date pace. Not against last month's total, which you only know after the fact, but against where you should be on day 14 to land on plan. A category running 30 percent ahead of pace on the 14th is a decision you can still make. On the 3rd of the following month it is a debrief.

Committed spend that has not hit the bank yet. This is the largest blind spot in most burn calculations. A signed annual contract, an approved purchase order and a headcount offer that has been accepted are all money you have already promised, and none of it appears in a cash-based burn figure until it clears. Teams that track approved purchase orders as committed spend see the obligation at the point of approval rather than at the point of payment, which is usually a month or more earlier.

Renewals landing in the next 60 days. Because they are lumpy and because they are the most cancellable part of your cost base, right up until the notice window closes. A renewal calendar with the correct dates on it is worth more than another burn dashboard, which is the argument made at length in software renewal management.

New recurring charges nobody approved. Individually small, collectively the thing that makes burn creep without a decision ever being taken. A new $400-a-month tool does not show up in a variance review. Twelve of them add nearly $5,000 to monthly burn, which on a 12-month runway is real money. The mechanics of finding them are in the SaaS subscription audit.

None of these require new accounting. They require someone to be told when a threshold is crossed rather than when the month is closed. That is the whole difference between a budget versus actual variance report, which explains what happened, and a budget alert, which arrives while the month is still in progress.

Is burn rate the same as net loss?

No, and the gap between them catches people out regularly. Net loss is an accrual figure. It includes non-cash items like depreciation, amortization and stock-based compensation, and it recognizes revenue when it is earned rather than when it is collected. Burn is pure cash movement.

In practice that means a company can post a modest accounting loss while burning heavily, usually because it prepaid annual contracts or because collections are slipping. It can also post a large accounting loss while burning very little, if most of the loss is stock compensation. If you are reporting to a board, give them both and label which is which, because a reader who assumes they are the same number will misread your position in whichever direction the difference runs.

Does burn rate include payroll?

Yes, and it usually dominates. Burn is a cash measure covering every operating outflow: payroll and the employer side of payroll taxes, contractors, software, rent, hosting, marketing, professional fees. At most early-stage companies payroll runs 60 to 80 percent of gross burn.

Two practical consequences follow from that concentration. First, meaningful burn reduction almost always means headcount, which is why "cut the burn" conversations are slower and more painful than the spreadsheet implies. Second, the non-payroll 20 to 40 percent is where changes can be made quickly, and it is also the part that is least watched, because it is spread across dozens of small recurring charges rather than sitting in one line. That is the part worth instrumenting.

A working routine

What this looks like in practice, monthly:

1. Compute gross and net burn from operating cash flows, excluding all financing activity.
2. Use a rolling three-month average for runway, not a single month, and note any month containing a third payroll or a large annual renewal.
3. Add committed but unpaid obligations to a separate line, so signed contracts and approved orders are visible before they clear.
4. List every renewal falling in the next 60 days, dated by its notice deadline rather than its renewal date.
5. Set thresholds on the categories that actually move, and have them alert someone mid-month rather than appearing in the close.
6. Report both burn and net loss to the board, labeled, so nobody conflates them.

The first two steps get the number right. The last four are the ones that give you time to do something about it, which is the only reason to measure burn at all. A burn rate you learn about after the quarter closed is a historical fact. A burn rate you can see moving is a decision you still get to make.