Microsoft reveals OpenAI accounts for 70% of AI sales, with $24B revenue run rate

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. OpenAI closed a record $122 billion funding round on March 31, 2026, which pushed its post-money valuation to $852 billion. Microsoft participated in that round alongside Amazon, NVIDIA, and SoftBank. The revenue engine is primarily ChatGPT subscriptions and API usage. Enterprise customers are paying for access to OpenA...