A Building Program Just Got a New Ruler
Microsoft told analysts on its latest earnings call that it is extending the useful life it assigns to data centers and office buildings from 15 years to 25, starting in fiscal 2027. The change sounds like an accounting footnote. It is actually the reason Microsoft's headline capital-spending number for calendar 2026 moved from roughly $190 billion to about $175 billion without a single server rack being cancelled.
The Numbers Before and After
Microsoft's own disclosures put the shift in three figures that did not move together before this quarter.
| Measure | Before | After / Latest |
|---|---|---|
| Depreciation life (data centers, offices) | 15 years | 25 years, from fiscal 2027 |
| Reported calendar-2026 capex | ~$190 billion | ~$175 billion |
| Leases signed, not yet started | $92.7 billion (prior year) | $329.1 billion (June 2026) |
Why a Longer Lifespan Shrinks the Capex Line
Under standard accounting rules, a lease only counts toward reported capex when it is classified as a finance lease. Stretch the useful life of the underlying building, and more of Microsoft's data-center deals reclassify as operating leases instead, which sit outside that capex figure even though the company is on the hook for the same rent. Microsoft was explicit that this is a classification change: management told analysts the underlying calendar-2026 investment plan is unchanged outside of it.
The 38-Gigawatt Target This Is Funding
The accounting shift lands alongside a physical expansion, not instead of one. Bloomberg reported this week that Microsoft is targeting 38 gigawatts of data-center capacity by 2032, more than triple the roughly 12 gigawatts it operates now, using a mix of self-built sites and leased capacity from neocloud partners including CoreWeave, Nscale, Lambda, Iren and Nebius. The $329.1 billion in leases signed but not yet commenced is the pipeline behind that target, most of it now classified in a way that will not show up in the capex line investors have been using to judge AI spending discipline.
What This Changes If You Read the Capex Numbers
If part of your job is comparing hyperscaler capex-to-revenue ratios to judge whether the AI buildout is rational, that comparison broke this quarter for Microsoft specifically. A $15 billion drop in the reported number carries no information about spending discipline; it reflects a longer depreciation schedule applied to the same physical commitment. Treat the 38-gigawatt target and the $329.1 billion lease backlog as the real measures of scale, and treat this year's capex figure as not directly comparable to last year's.
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