Inspired by @Lost_Robin's blog on the population of the wizarding world. . . 

We all know that JRK’s strengths lie in worldbuilding and storytelling--not in math and logistics. Still, her word is canon, so I’ll work with her ideas as I grapple with the baffling world of

HOGWARTS SCHEDULES

There are a variety of Hogwarts schedules on the Internet including the ability to make your own. They show the daily schedule having anywhere from four to eight academic blocks per day with lunch in the middle. With the exception of Monday morning during fifth year (in which the students attended two double classes before lunch), JRK seems to have visualized three blocks before and three blocks after the midday meal. 

6 blocks a day x 5 days = 30 academic blocks a week.

Assumption: each subject will have 3 three academic blocks per week.

THE STUDENTS:
Years 1 and 2-, a student takes 7 subjects; however, Astronomy is at night. (We’ll assume 2 academic blocks for a practical at night and one for theoretical during the normal school day.)

7 subjects x 3 blocks per subject = 21 blocks (including 2 at night) No problem!

Years 3-5- a student takes 9 subjects. (7 plus 2 electives)

9 subjects x 3 blocks per subject = 27 blocks (including 2 at night) Again no problem!

This also makes sense for Hermione to need a time turner because she would need 9 additional blocks beyond the typical schedule which obviously don’t fit in the third year schedule.

Years 6-7-a student takes less classes but I will assume spends more time in each class. Hermione Granger took seven, so we’ll use that number.

7 subjects x 4 blocks per subject =28 blocks

THE TEACHERS:
So, everything looks feasible from the students’ perspective. Now, let’s look at the teachers because we all know that teachers are overworked and underpaid (although we can assume that they get free room and board which is more than I get.)

For each core subject, there are two classes per year (as the houses are always paired with another house for each class) However, NEWT classes seemed to be grouped together assuming less students move onward.

2 classes per year x 3 blocks per week x 5 years = 30 blocks.

This is exactly the number of blocks allocated and doesn’t include the 8 blocks for NEWT students. Plus, one would assume that we need an additional remediation class for students who want to take their OWLs again, so this would mean an additional 12-14 blocks needed in their schedule. This could work if the teachers never had a planning period and taught all of Saturday and at least half of Sunday. (We won’t even talk about Umbridge’s schedule fifth year as both DADA teacher and High Inquisitor. She must have used a Ministry time turner.) 

LARGE CLASS SIZES-
Plus if one takes into account JRK’s interview where she said there were approximately 1000 students at Hogwarts at any given time. . . 

1000 students/7 years = 142.86 students per year (rounding to 142)
142 students per year/ 4 houses = 35 students per house

Since classes are combined with another house for OWL level, this means 70 students in their classes!

Unless of course, we want a reasonable class size of 35. Then the teachers will need to teach 4 of each year instead of 2 (and we’ll say 2 NEWT classes for each year and 1 remediation class.)

4 classes per year x 3 blocks per week x 5 years = 60 blocks + 20 for NEWT and remediation = 80 blocks.

Now, let’s assume that each academic block is 45 minutes (and there is not time in between to switch classes)

45 minutes x 80 blocks = 3600 minutes or 60 hours of teaching a week!

This doesn’t include writing lesson plans, grading papers, cleaning up their messes, monitoring hallways, faculty meetings, discipline and sponsoring the various clubs. 

So, I say HAIL HOGWARTS TEACHERS! Tell Dumbledore that you deserve a raise!