Burn rate is the rate at which a business consumes its cash reserves over a period, stated by convention as an amount per month. It comes in two versions that give different answers: gross burn is the total operating cash going out over the period, and net burn is that outflow net of the cash coming in, so net burn is the net decline in cash from operating activity. Dividing cash on hand by net burn gives runway, the number of months the current balance covers at that rate.
Gross Burn and Net Burn
The two versions answer different questions, so a burn rate quoted without saying which one is meant is not a figure anyone can use. Gross burn counts only money leaving, so payroll, rent, software and everything else paid to operate go into it and revenue is ignored. Net burn subtracts the cash received over the same period, which means it moves with collections as well as with spending, and it is the version runway is built on.
Neither version is defined by an accounting standard, so the period and the treatment of one-off items have to travel with the number. A month carrying an annual insurance premium or a quarterly tax payment produces a burn rate that says more about when a payment fell than about the rate at which the business runs.
Where the Figures Come From
Both versions are read off cash that actually moved rather than off the accrual result. The statement reporting those movements is the cash flow statement, and the operating subtotal it lands on is worked through in the operating cash flow formula. Where that section is presented as a reconciliation from net income, it takes the shape set out in the indirect method.
Burn rate appears on none of the financial statements. The SEC’s investor guide makes the general point, asking why terms such as the current ratio and operating margin do not show up on financial statements and answering that investors calculate them from information on the statements (SEC, Beginners’ Guide to Financial Statements). Burn rate sits in that group, and the FASB Statement that established the statement of cash flows does not use the term at any point (FASB, Statement of Financial Accounting Standards No. 95). It is management’s own measure, so the question a firm can settle is not whether the figure agrees with a standard but whether it was built the same way twice.
For a client whose runway is short the figure stops being an internal dashboard reading and starts feeding an assessment with reporting consequences, because conditions of that kind are among those weighed in the going concern evaluation management makes each reporting period.
A Worked Example
Say a business opens a month with the cash shown below, pays out the operating amount shown and collects the amount shown from customers.
Opening cash 240,000
Operating cash paid out 86,000
Cash collected from customers 54,000
Gross burn = 86,000
Net burn = 86,000 - 54,000 = 32,000
Runway in months = 240,000 / 32,000 = 7.5Gross burn and net burn differ here by everything the business collected, which is why the two are never interchangeable. Runway falls out of the net figure alone, so a collection landing a week late or a payment deferred into the following month moves it without anything about the business having changed. The runway figure also assumes nothing else moves through the cash account, so a loan drawn or a piece of equipment bought over the same month changes it too.
What Burn Rate Is Not
Burn rate measures consumption across a period, and the measures it sits closest to are read differently, so swapping one in changes the answer.
The liquidity ratios set current assets against current liabilities on one balance sheet at one date, so they report cover at a moment and say nothing about how fast cash leaves. Net working capital is that same date-stamped comparison expressed in dollars instead of as a quotient. The cash conversion cycle does measure movement, but it counts days between paying for inputs and collecting on the sale rather than dollars per month.
A net loss is not a burn rate either. Loss is the accrual result of the period, burn is cash that moved, and the two part company whenever a receivable, a payable or a non-cash charge sits between an entry and its cash. Under accrual accounting a profitable month can still be a heavy burn month. Run rate is the closest name to trip over. It annualizes a period’s current figures, most often revenue, so it is a projection method rather than a measure of cash going out.
Common Questions
The rate at which a business consumes cash, stated as an amount per month unless another period is named alongside it. Asking which version is meant is part of reading the answer, because gross burn and net burn are both called the burn rate.
Take the cash figures for a period rather than the accrual ones. Gross burn is the operating cash paid out over that period. Net burn is the same amount less the cash received over it. Divide either by the number of months in the period to state it monthly, then divide cash on hand by net burn to reach runway.
There is no defined level, and the figure means nothing on its own. The question a firm can answer is the runway one: how many months the cash on hand covers at the current net burn, and whether that is longer than the time it would take to change the number.
There is no normal figure to compare against. Two businesses can report the same burn rate on different definitions, different periods and different treatments of one-off payments, so a comparison is only worth making where the basis is stated on both sides. The same business read across its own earlier months is the more useful test.
Accountably places trained offshore accountants and tax preparers inside US CPA and EA firms, and a firm can put a block of its own monthly close and cash reporting work through a trial task before anything client facing depends on it.
