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L.6 · INTERMEDIATE · 3 MIN

Free Cash Flow: The Five Definitions That Matter

"Free cash flow" is one of the most-used terms in investing and one of the least-defined. There are at least five common definitions, each appropriate for a different question. The investor who picks the wrong definition for the question being asked will overstate or understate the answer by 30-50% and not know it.

Quiz · 5 questions ↓
§ 01

The five flavors: (1) FCFF — free cash flow to the firm; the right input for an enterprise-value DCF. (2) FCFE — free cash flow to equity; the right input for an equity DCF. (3) OCF − CapEx — the practitioner's quick screen; conservative when SBC is small, optimistic when SBC is large. (4) EBITDA − CapEx — useful for comparing operational cash quality across companies with different capital structures. (5) Owner Earnings — Buffett's lens; subtracts SBC and uses maintenance capex only. Owner Earnings is the most conservative; FCFF is the most enterprise-comparable.

§ 02
FlavorFormulaBest for
FCFFEBIT × (1 − tax) + D&A − ΔWC − CapExEnterprise-level DCF when capital structure may change
FCFENet income + D&A − ΔWC − CapEx + Net BorrowingEquity DCF for stable-leverage companies
OCF − CapExOperating cash flow − total capexQuick screen; comparable across most reported statements
EBITDA − CapExEBITDA − CapExOperational cash quality across mixed capital structures
Owner EarningsNet income + D&A − maintenance CapEx − SBC + non-cash adjustmentsLong-horizon investor lens; most conservative
§ 03

Worked example — Vanmark Communications reports OCF $1.2B, CapEx $700M, SBC $250M. OCF − CapEx is $500M. But: SBC ran 6% of revenue, and management discloses that ~$200M of capex is growth (new tower buildout) while $500M is maintenance (existing-network sustaining). Owner Earnings = OCF $1.2B − maintenance capex $500M − SBC $250M = $450M. The headline screen ($500M) is 11% above the conservative shareholder lens ($450M) — a small gap here, but at heavy-SBC software names the gap regularly hits 40%+. Always disclose which definition you used.

§ 04

Going Deeper — when the flavors disagree, the disagreement is the signal. If Owner Earnings is meaningfully below OCF − CapEx for several years running, the gap is almost always either heavy stock-based comp (read: equity dilution funding the income statement) or aggressive capex classification (growth capex labeled as maintenance to flatter the screen). Either way, the headline number is hiding a real cost. AI prompt: "For this ticker, compute OCF − CapEx and a conservative Owner Earnings figure across the past five years. Show me the year with the largest gap and explain whether stock-based comp, capex classification, or working-capital tactics drove the divergence."

§ 05
Pick any tech-heavy stock you own. Compute three numbers from the latest 10-K: OCF − CapEx, EBITDA − CapEx, and a rough Owner Earnings (subtract SBC and assume 70% of capex is maintenance). Compare against the company's own "adjusted free cash flow" headline. The gap between the four definitions usually exceeds 25%.
§ 06
A SaaS company reports "adjusted free cash flow" of $300M, OCF − CapEx of $260M, and Owner Earnings of $140M. Which framing is most defensible for an investor sizing a position?
§ 07

The investor's discipline: pick one FCF definition for the question you are asking, disclose it explicitly in the memo, and stay with it across companies you compare. Switching definitions across names — Owner Earnings on one, OCF − CapEx on another — is one of the most common ways analysts accidentally compare apples to oranges and call themselves rigorous.

Five questions · AI feedback

Sit with the ideas.

Tirebridge Materials reports operating cash flow of $400M, capex of $250M, and stock-based compensation of $80M. Two analysts compute free cash flow differently — one says $150M, the other says ~$70M. Which framing best explains why both can be defensible at the same time?

Why:
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