Free cash flow is the amount of cash a business generates after paying its operating expenses and maintaining or expanding its physical assets. It's the cash that's actually available to shareholders — for dividends, share buybacks, debt repayment, acquisitions, or simply sitting in the bank as a safety cushion.
Unlike net income, which is an accounting construct influenced by depreciation schedules, revenue recognition policies, and one-time charges, free cash flow measures what actually happened to the company's bank account. Cash came in from customers, cash went out for expenses and equipment, and what's left is free cash flow.
The Formula
Free Cash Flow = Operating Cash Flow - Capital Expenditures
Both components come directly from the cash flow statement in the 10-K or 10-Q:
- Operating Cash Flow (OCF): The net cash generated by the company's core business operations. It starts with net income, adds back non-cash charges (depreciation, stock-based compensation), and adjusts for changes in working capital (accounts receivable, inventory, accounts payable). This is the first section of the cash flow statement.
- Capital Expenditures (Capex): Cash spent on property, plant, and equipment (PP&E). This appears in the investing activities section, usually as "Purchases of property and equipment" or "Capital expenditures." It's reported as a negative number (cash outflow).
Worked Example
From a company's 10-K cash flow statement:
- Net income: $80 million
- Depreciation & amortization: +$25 million
- Stock-based compensation: +$15 million
- Changes in working capital: -$10 million
- Operating Cash Flow: $110 million
- Capital expenditures: -$35 million
- Free Cash Flow: $75 million
Notice: net income is $80 million, but FCF is $75 million. The $5 million difference comes from working capital changes and the excess of depreciation + SBC over capex. In many companies, this gap is much larger.
Why Free Cash Flow Matters More Than Net Income
Cash Is Harder to Fake
Revenue recognition rules allow companies flexibility in when they recognize revenue. A company can book a $10 million sale today even if the customer won't pay for 90 days. That $10 million shows up on the income statement immediately but doesn't appear in operating cash flow until the cash is collected. This timing flexibility makes net income susceptible to manipulation in ways that cash flow is not.
The most reliable forensic accounting check: compare net income trends to operating cash flow trends. If net income is growing steadily but operating cash flow is flat or declining, the company may be using aggressive accrual accounting to inflate earnings. This divergence has preceded accounting scandals at companies like Enron, WorldCom, and Luckin Coffee.
FCF Funds Shareholder Returns
A company can only sustainably pay dividends, buy back shares, or reduce debt from free cash flow. A company that pays $50 million in dividends but generates only $30 million in FCF is funding the shortfall by borrowing or liquidating assets — neither of which is sustainable. Checking FCF against dividends paid (both on the cash flow statement) tells you whether the dividend is safe.
FCF Drives Intrinsic Value
Discounted cash flow (DCF) models — the foundation of fundamental valuation — use free cash flow as their input, not net income. The intrinsic value of a business is the present value of all future free cash flows it will generate. This is why investors care about FCF growth rates: a company growing FCF at 15% per year is worth more than one growing FCF at 5%, all else being equal.
Free Cash Flow Yield
FCF yield tells you how much free cash flow you're getting per dollar of stock price:
FCF Yield = Free Cash Flow per Share / Stock Price
Or at the company level: FCF Yield = Free Cash Flow / Market Cap
A 5% FCF yield means the company generates $5 in free cash for every $100 of market value. Compare this to the 10-year Treasury yield — if a company's FCF yield exceeds the risk-free rate by a comfortable margin, you're being compensated for the equity risk.
High FCF yield stocks (8%+) are often undervalued — or they're in declining businesses where FCF will deteriorate. Low FCF yield stocks (1-2%) are either expensive or are growth companies reinvesting heavily. Context matters.
Maintenance Capex vs Growth Capex
Not all capital expenditures are created equal. Maintenance capex — the spending required to keep existing operations running (replacing worn equipment, upgrading facilities) — is a true cost that must be subtracted. Growth capex — spending to expand the business (new factories, new markets, new product lines) — is an investment that should generate future returns.
The standard FCF formula subtracts total capex without distinguishing between the two. This penalizes companies that are investing heavily in growth. A more nuanced metric, sometimes called "owner earnings" (a term coined by Warren Buffett), subtracts only maintenance capex:
Owner Earnings = Operating Cash Flow - Maintenance Capex
The problem: companies rarely disclose the split between maintenance and growth capex. You can estimate it — depreciation expense is a rough proxy for maintenance capex — but it requires judgment. Look in the MD&A section of the 10-K, where management sometimes discusses the purpose of capital expenditures.
Free Cash Flow Red Flags
Persistent negative FCF. Some companies (especially pre-revenue biotech and early-stage tech) have negative FCF by design — they're investing in growth. But a mature company with negative FCF is consuming cash to survive, which means it needs external financing (dilutive equity raises or increasing debt) to continue operating.
Net income much higher than OCF. If net income is $100 million but operating cash flow is $30 million, the company is booking profit it isn't collecting in cash. Check accounts receivable (are they growing faster than revenue?), inventory (is it building up?), and accrued liabilities (are they being deferred?).
Declining FCF margins. A company whose FCF margin was 20% three years ago, 15% two years ago, and 10% last year is spending more to generate the same revenue. Either the business is becoming less efficient or management is over-investing.
FCF lower than dividends + buybacks. If a company returns $80 million to shareholders (dividends plus buybacks) but only generates $50 million in FCF, it's borrowing or selling assets to fund returns. Check the balance sheet: is debt increasing year over year? That's the funding source.
Finding FCF in SEC Filings
Free cash flow is not a GAAP line item — you calculate it from two numbers that are:
- Open the 10-K or 10-Q to the Statement of Cash Flows
- Find "Net cash provided by (used in) operating activities" — this is OCF
- In the investing activities section, find "Purchases of property and equipment" — this is capex
- Subtract capex from OCF = FCF
Many companies also report FCF in their earnings press releases and investor presentations as a non-GAAP metric, with a reconciliation to operating cash flow. Some report "adjusted free cash flow" that excludes certain items — apply the same scrutiny as with adjusted EBITDA.
On Brefyr, the AI pipeline extracts financial data from 10-K and 10-Q filings for 7,600+ companies, making it easier to compare cash flow metrics across your tracked stocks without manually parsing each filing.