Microsoft’s AI business is booming. But peel back the numbers and you’ll find that roughly 70% of that growth traces back to a single partner: OpenAI.
OpenAI’s revenue has hit approximately $24.1 billion on an annualized basis in fiscal 2026, translating to about $2 billion rolling in every month.
The numbers behind the partnership
Microsoft’s broader AI business is running at somewhere between $37 billion and $40 billion in annualized revenue as of mid-2026. If OpenAI accounts for 70% of the AI sales portion, the math is straightforward: remove OpenAI from the equation and Microsoft’s AI story looks dramatically different.
Microsoft reported that OpenAI-related commitments represented roughly 45% of its $625 billion commercial cloud backlog as of Q2 fiscal year 2026. That’s not a typo. Nearly half of Microsoft’s future cloud revenue pipeline is tied to one company.
