How to calculate the max number of worker threads in SQL Server?
It seems someone has changed the maximum worker threads setting to a non-default value, which will override the default calculated value. The current configured value can be determined with:

EXEC sp_configure 'max worker threads';


I'll add the value is sometimes set mistakenly as a knee-jerk reaction to address symptoms rather than the underlying cause. Some valid reasons for configuring the value are called out in the documentation but the default calculation is appropriate for most workloads.