In Calendar Beta, you can now easily see how many hours each user is assigned, as well as how many hours are still unassigned. A user's assigned hours are displayed directly under their name in the Users and User Groups column:
The hours displayed in the Users and User Groups column are only for work orders in the week you’re currently viewing, not for all work orders in the calendar. Further, a user or group’s assigned hours only include work orders that are assigned directly to them, without any other assignees.
To learn more, see Assigned hours in the calendar.