How many classes do most students have per week in college?

Can it be 4-5 classes per week? or maybe two-three days of class per week?

Depends. If it’s a semester, trimester, or quarter system, the frequency or length of classes will be different accordingly. It also depends on the number of credit hours taken, whether or not the schedule includes labs.

It can even matter what subject and level: an intro humanities might meet 2-3 x / week, and an upper level class in the same subject might be 1 x / week. There is also a difference between # of days & # of classes, and it can change ter by term: you could have most of your classes on M/W one term and spread out across the week another.

On the semester system 12 credit hours is considered the minimum for full time enrollment. Assuming a program requires 120 credit hours to graduate (as many do) this would be an average of 15 hours per semester.

Assume a school on semesters.

A 3 credit class might meet 2-3x/week. Each class could be 45-50 min long. Some classes might have an additional add-on discussion/small group that the student has to sign up for. That could be another 45-50 min class.

Some 4-5 credit classes might have 3-4 classes/week with a required 2-4 hr long lab. The labs might meet 1-2 times/week.

Then there are those strange classes. My dd had a 2 credit music class that met 2x/week for 80 min each class. With an add-on 2 hr rehersal 2x/week.

There are some intro/welcome-to-college classes that might only be 1 credit but meet 1x/week for 2-3 hrs.

A typical college student in a semester system might have 15 credits per semester. These credits are the equivalent of 5 classes x 3 academic hours (50 min) per week x 15 weeks.
Some classes are M W F at 50 min per class. Some are T Th and are 75 min per class.
Sometimes students have classes all 5 days, or 3 days or whatever the schedule for those classes is.

Keep in mind that it is assumed for every hour in class, you have 2-3 hours of reading/studying/homework.