In their latest available annual report, the Wikimedia Foundation reported that in 2024 they brought in $185M in revenue/donations, of which they spent $178M. Of that $178M, $106M was spent on salaries and benefits, and $26M on awards and grants. So, that accounts for 75% of their spending. "Internet hosting" is listed at only $3M though there are other line items such as "Professional service expenses" at $13M that probably relate to running Wikipedia too.

Scroll down to the "Statement of activities (audited)" section:

https://wikimediafoundation.org/annualreports/2023-2024-annu...