Guide

Capital expenditures (CapEx) explained

Harbor Manufacturing looked inexpensive on a trailing P/E of 11x in late 2025. Operating margin was stable, and management guided “disciplined investment.” The cash flow statement told a different story: capital expenditures had jumped from $180M to $410M over two years while revenue grew only 8%. Analysts who subtracted the full capex line from operating cash flow modeled negative free cash flow (FCF) through 2028 and flagged a dividend cut risk. After splitting maintenance capex (sustaining existing capacity) from growth capex (a new fabrication line with disclosed IRR hurdles), normalized owner earnings rose and the implied DCF overvaluation shrank from 34% to 9%. CapEx is where accounting profit and economic cash often diverge most sharply.

Capital expenditures (CapEx) are cash outlays to acquire or upgrade long-lived physical or intangible assets — factories, servers, aircraft, software developed internally — that will generate benefits over multiple years. Unlike operating expenses (wages, rent, marketing), capex is capitalized on the balance sheet and expensed gradually through depreciation and amortization on the income statement. That timing mismatch is why a company can report healthy earnings per share (EPS) while burning cash. This guide covers where capex appears in financial statements, maintenance versus growth splits, intensity ratios, capitalized software, the Harbor Manufacturing refactor, a technique decision table versus OpEx and leasing, pitfalls, and an investor checklist.

Where capex lives in the financial statements

On the cash flow statement, capex almost always appears under investing activities as “purchases of property, plant and equipment” (PP&E) or similar wording. US GAAP reports it on a cash basis — when cash leaves the bank, not when a vendor invoices. Some companies also break out “capitalized software development costs” or “acquisition of intangible assets” in the same section.

On the balance sheet, gross PP&E increases by capex and decreases by accumulated depreciation. The roll-forward every analyst should know:

Ending PP&E (net) = Beginning PP&E + Capex − Depreciation − Impairments ± Disposals

If reported capex plus depreciation does not reconcile with the change in PP&E, check footnotes for asset sales, currency translation, or reclassifications. The cash flow statement guide walks through how operating, investing, and financing sections link together.

On the income statement, you will not see capex directly. You see its aftermath: depreciation and amortization (D&A) reducing operating income. High reported EBITDA can coexist with heavy cash capex because EBITDA adds back D&A but ignores the cash spent replacing or expanding assets. That is one reason EBITDA is a poor proxy for cash generation in capital-intensive businesses.

Maintenance capex vs growth capex

Companies rarely label the split in the 10-K, but investors need it to estimate sustainable cash earnings:

Maintenance (sustaining) capex — spending required to keep current revenue and capacity intact: replacing worn machinery, routine datacenter refreshes, regulatory-mandated environmental upgrades. If you do not spend it, the asset base decays and revenue eventually falls.
Growth capex — discretionary investment for new capacity, geographic expansion, product lines, or efficiency projects with incremental return hurdles. It should earn returns above the cost of capital or it destroys value.

A practical shortcut when management does not disclose the split: approximate maintenance capex as depreciation and amortization (sometimes adjusted for inflation and asset mix). Warren Buffett's “owner earnings” concept uses reported earnings plus D&A minus estimated maintenance capex. Growth capex is then total capex minus that maintenance estimate.

Caveats matter. Depreciation schedules are accounting constructs — a 30-year-old plant may need more cash than its book depreciation suggests. Conversely, cloud and software businesses may capitalize engineering labor; their “capex” behaves more like product development than a steel mill upgrade. Always read MD&A capex guidance and project tables in the 10-K.

Capex intensity ratios

Raw dollar capex is hard to compare across companies. Normalized ratios help:

Capex / Revenue — what fraction of sales is reinvested in the asset base. Semiconductors and utilities often run 15–25%; asset-light software may run under 5% (excluding capitalized software).
Capex / Depreciation — ratios above 1.0x suggest net expansion; below 1.0x may mean underinvestment or asset-light aging.
Capex / Operating Cash Flow — how much of operating cash is consumed by reinvestment before dividends and buybacks.
Change in PP&E / Revenue growth — links balance sheet investment to top-line momentum.

Compare ratios to a company's own five-year history and to sector peers. A sudden spike in capex intensity without a credible growth narrative is a yellow flag — especially when paired with rising working capital needs or higher debt funding the build-out.

Capitalized costs vs operating expenses

Accounting rules draw a line between expensing now and capitalizing for later. Salaries for factory workers assembling products are OpEx. Salaries for engineers building internal software may be capitalized if specific GAAP/IFRS criteria are met. R&D is usually expensed under US GAAP (except certain software development stages), which makes pharma and biotech look like chronic cash burners even when they are investing in future products.

Aggressive capitalization inflates near-term earnings and understates capex in the investing section until impairments hit. Red flags include capex growing faster than PP&E, rising capitalized software with vague amortization schedules, and large gaps between earnings quality metrics and cash conversion.

Leasing complicates comparisons. Under ASC 842, many operating leases now appear as right-of-use assets with associated depreciation and interest — but the cash lease payment sits in operating or financing cash flow, not always as traditional capex. When benchmarking capex intensity across peers, check whether competitors own assets versus lease them.

CapEx and free cash flow

The standard FCF bridge:

Free Cash Flow = Cash from Operations − Capex

Subtracting all capex answers: “What cash is left after everything management chose to invest?” Subtracting only maintenance capex answers: “What cash could owners extract without shrinking the business?” Both are valid; the choice depends on whether you model a steady state or a growth phase.

In a DCF model, explicit forecast capex should match the revenue story. If you project 12% revenue CAGR but capex falls to 2% of sales, you are implicitly assuming rising margins from underinvestment — a common modeling error. Terminal-value assumptions often set terminal capex equal to terminal depreciation; verify that matches the company's stated maintenance needs.

For dividend and buyback capacity, pair capex analysis with FCF yield and payout ratios. A high dividend yield funded by deferred capex is a classic value trap.

Harbor Manufacturing refactor

Harbor's 2025 10-K disclosed $410M total capex against $195M depreciation. Management attributed $240M to a new fabrication line (growth) and $170M to sustaining upgrades (maintenance). The equity research team initially modeled FCF as CFO − $410M, yielding −$85M and a perceived 40% dividend cut probability.

The refactor:

Used five-year average maintenance capex ($155M) as a sanity check on the $170M management figure.
Built a separate NPV model for the growth line using disclosed 18% IRR hurdles and 2027 production ramp.
Computed owner earnings as CFO − $170M maintenance capex = +$155M, positive and covering the dividend 1.4x.
Stress-tested growth capex overruns (+20%) and two-year delay scenarios.

Result: the stock moved from “cheap earnings, broken cash” to “fairly priced transition story.” Position sizing tightened; false dividend-cut alarms dropped from 6 names in the industrial sleeve to 1. The lesson: headline negative FCF during a disclosed growth cycle is not automatically bearish — but unlabeled capex spikes without return transparency usually are.

Technique decision table

Question	Use capex analysis when…	Consider alternatives when…
Is cash earnings sustainable?	Business owns PP&E; capex is material vs CFO	Asset-light model; capex <3% of revenue
Valuing mature utility or industrial	Maintenance capex ≈ depreciation; regulated return frameworks	Early-stage growth where all spend is investment
Comparing peers	Normalize capex/revenue and reconcile leasing differences	Peers use different ownership vs lease structures
Screening cheap stocks	Pair P/E with FCF and capex intensity trends	P/E alone in a capex upcycle
Funding dividends	CFO − maintenance capex covers payout	Growth funded entirely by equity raises

Common pitfalls

Treating all capex as maintenance — understates growth investment and overstates owner earnings.
Equating depreciation with maintenance capex blindly — asset age, inflation, and technology obsolescence break the shortcut.
Ignoring capitalized software and intangibles — especially in tech, real reinvestment hides outside PP&E line items.
Using EBITDA as cash proxy in heavy industries — ignores the cash cost of staying in business.
Missing lease-adjusted comparisons — owned vs rented assets distort peer capex ratios.
Forecasting falling capex without a story — DCF models that magically shrink reinvestment inflate terminal value.
Overlooking maintenance backlog — deferred capex can boost near-term FCF at the expense of future reliability.

Investor checklist

Pull three years of capex from the cash flow statement investing section.
Reconcile capex to the PP&E roll-forward in the 10-K.
Read MD&A for maintenance vs growth splits and project IRR disclosures.
Compute capex/revenue, capex/depreciation, and capex/CFO ratios vs history.
Estimate maintenance capex (management figure or D&A proxy) separately.
Calculate owner earnings: CFO minus estimated maintenance capex.
Check whether growth capex is funded by operating cash, debt, or equity.
Compare capitalized software and intangibles trends for tech-heavy names.
Adjust peer comparisons for lease versus own structures.
Stress-test DCF with +20% capex and one-year project delay scenarios.
Verify dividend and buyback coverage using maintenance-adjusted FCF.
Flag capex intensity spikes without matching revenue or margin guidance.

Key takeaways

CapEx is cash spent on long-lived assets; it hits the cash flow statement immediately but the income statement only through depreciation.
Splitting maintenance from growth capex is essential for owner earnings and dividend safety analysis.
Harbor Manufacturing's refactor cut perceived DCF overvaluation from 34% to 9% by modeling growth investment separately from sustaining spend.
Intensity ratios (capex/revenue, capex/depreciation) must be compared to sector norms and a company's own history.
Pair capex work with FCF, DCF assumptions, and earnings quality — headline EPS alone misses the reinvestment story.