AFFO: From FFO to Sustainable REIT Cash Flow

Introduction

FFO solved one problem with REIT accounting and quietly created another. By adding back non-cash depreciation, FFO fixed the distortion where GAAP treats appreciating buildings as if they wear out like factory equipment. But in doing so it swung too far: FFO implicitly assumes real estate needs no ongoing investment at all, when in reality every building consumes cash every year just to keep earning. Roofs get replaced, HVAC systems get overhauled, lobbies get renovated, and landlords pay for tenant build-outs and broker commissions every time a lease turns over. AFFO (Adjusted Funds From Operations) is the metric that puts those costs back in.

The adjustment strips out recurring capex, tenant improvements (TIs), leasing commissions (LCs), and straight-line rent adjustments to arrive at a number that sits much closer to free cash flow in the corporate-finance sense than FFO does. That is exactly why institutional REIT investors weight AFFO most heavily: it is the metric that actually answers whether the dividend is funded by sustainable cash. It is also the cleaner basis for cross-sector trading comps, because it captures the wide capex differences between sub-sectors that FFO papers over, and REIT M&A accretion analysis treated in AFFO terms is the more rigorous standard.

The standard AFFO formula starts with FFO and subtracts each of the recurring items that FFO excludes:

Each line addresses a specific gap between FFO and economically sustainable cash flow.

AFFO (Adjusted Funds From Operations)

The refinement of FFO that subtracts recurring capital expenditures, tenant improvements, leasing commissions, and straight-line rent adjustments to approximate the cash a REIT can sustainably distribute. Unlike FFO (which is industry-standardized by Nareit), AFFO is calculated by each REIT using its own definition of "recurring," which means cross-REIT AFFO comparisons require normalization. P/AFFO is the most-watched REIT trading multiple at the institutional-investor level.

Recurring Capital Expenditures

Recurring capex is the ongoing spend required to keep a property income-producing. Standard examples: roof replacements at end of useful life, HVAC overhauls, parking-lot resurfacing, elevator modernization, mechanical-system updates, and general building-system maintenance. The recurring portion is distinct from growth capex (spending that genuinely expands the property's earning power, like adding floors or building amenities that justify higher rents); growth capex is treated as investment rather than maintenance and is therefore included differently in AFFO frameworks.

Typical recurring capex reserves vary by sub-sector:

Tenant Improvements and Leasing Commissions

TIs and LCs are the cash outlays a landlord makes to attract or renew tenants. They are capitalized for GAAP purposes and amortized over the lease term, but the cash outflow is immediate and recurring across the property's life. The AFFO adjustment subtracts the recurring portion of TIs and LCs to reflect the ongoing cash drag from re-leasing activity.

The magnitude varies by sub-sector and by lease structure. Office buildings with shorter-duration leases and higher TI packages absorb meaningful recurring TI/LC; industrial buildings with long-duration triple-net leases absorb less; ground-leased trophy assets effectively absorb zero. Cross-sector AFFO comparisons that ignore the TI/LC differential systematically overstate the dividend-coverage capacity of office REITs relative to industrial REITs.

Straight-Line Rent Adjustments

GAAP requires REITs to straight-line rent across the lease term: a 10-year lease with annual rent steps of $50, $52, $54, etc. gets averaged into a single straight-line rent that the REIT recognizes evenly across the lease. Mechanically, the recognized figure is just total contractual rent over the term divided by the number of years:

The GAAP recognition typically runs higher than the actual cash collection in the early lease years (when contract rents are lower) and lower than the actual cash collection in the late lease years (when contract rents are higher). The cash-vs-GAAP gap this creates is precisely the straight-line rent adjustment that AFFO backs out.

FFO uses the GAAP straight-line rent figure, which produces an FFO measure that includes non-cash revenue accruals in the early lease years. AFFO subtracts the straight-line rent adjustment to align with actual cash collected, producing a more cash-realistic measure. The adjustment can be positive or negative depending on where the portfolio's leases sit in their respective lease terms.

The AFFO refinement barely matters when you compare REITs inside the same sub-sector. All industrial REITs carry similar recurring capex and TI/LC patterns, so a P/FFO comparison between two of them holds up reasonably well. The refinement earns its keep across sub-sectors, where the capex intensity differs enough that FFO comparisons actively mislead. As a rough calibration, AFFO typically lands at 95-100% of FFO for triple-net landlords, 85-95% for industrial and multifamily, and 70-85% for office, retail, and lodging. The same dollar of FFO simply buys very different amounts of distributable cash depending on what the REIT owns, which is one reason real estate valuation behaves differently from standard corporate comps.

Consider a multifamily REIT trading at 16x P/FFO and an office REIT trading at 12x P/FFO. On the surface the office REIT looks cheaper. On a P/AFFO basis the picture often reverses: the office REIT's heavier recurring capex and TI/LC obligations pull its AFFO roughly 25-30% below FFO, while the multifamily REIT's lighter capex pulls AFFO down only 10-15%. The multiples can converge to something like 18x P/AFFO for multifamily against 17x for office, far closer than the P/FFO spread implied and a truer read of comparable cash flow. An analyst who screens only on P/FFO will keep flagging office REITs as cheap and walking into the recurring-capex trap; checking P/AFFO alongside it is what catches the error.

The AFFO payout ratio (annual dividends per share divided by AFFO per share) is the most-watched dividend-coverage metric at the institutional-investor level:

The inverse is dividend coverage (how many times AFFO covers the dividend), and a payout ratio below roughly 80% is generally read as comfortably sustainable. Investment-grade REITs typically run AFFO payout ratios in the 75-95% range, leaving 5-25% of AFFO retained after the dividend for capex above the recurring reserve, debt service, and modest reinvestment. Payout ratios above 100% (where the dividend exceeds AFFO) signal that the dividend is being funded partly through capital recycling, equity issuance, or debt rather than through sustainable cash flow, which is a structural warning sign for dividend sustainability.

This is why AFFO coverage is the leading indicator analysts watch ahead of a dividend cut. A REIT whose AFFO payout ratio creeps above 100% for several consecutive quarters is structurally exposed even when its FFO coverage still looks comfortable, because the FFO number was never net of the capex the REIT has to keep funding. The mirror case is just as informative: a REIT running 60-75% AFFO coverage has room to raise the dividend out of earnings growth alone, without leaning on new equity or debt.

That brings the analysis back to the one trap waiting in the metric itself.