Maintenance Capex
The portion of capital spending a company must make just to maintain its current productive capacity, not to grow it.
What it is
Maintenance capex is the capital expenditure a business needs to keep its existing asset base and competitive position intact at current sales volumes, as opposed to growth capex, which adds new capacity, locations, or products. Think of it as the real cash cost of standing still. It is the practical counterpart to depreciation: the actual cash a company must lay out to replace assets its operations wear out. Companies almost never disclose the split, so analysts estimate it.
Why it matters
It is the cash a business genuinely needs to reinvest before any is left for owners, and it sits at the heart of Warren Buffett's "owner earnings" (introduced in his 1986 Berkshire Hathaway letter): roughly net income plus non-cash charges minus maintenance capex. A company can look free-cash-flow rich simply because it cut maintenance spending, quietly degrading its assets. The pitfall: because the figure is estimated, not reported, it is subjective and easy to game. Two analysts can produce very different numbers for the same firm, and management can flatter near-term cash flow by deferring upkeep, so always check whether the estimate is realistic versus the asset base.
How it's calculated
Since firms rarely report it, you estimate it by subtracting estimated growth capex from total capex on the cash flow statement. A common shortcut is to use depreciation as a proxy, on the logic that depreciation approximates the cost of replacing aging assets. A more rigorous "footprint" method (Bruce Greenwald's) takes the historical average gross PP&E-to-sales ratio, multiplies it by the year's sales increase to isolate growth capex, then subtracts that from total capex.
How Quintarthai uses it
A company's deep-analysis page at /app/ shows reported capital expenditure and depreciation from the cash flow statement, which let you sanity-check a maintenance-capex estimate and the owner-earnings it feeds. Use the Knowledge Base to connect it to owner earnings and free cash flow.