On an average (non-Freshman) semester, how many courses do you take in your major compared to non-major courses (general ed requirements, diversity requirements, electives, etc.) Or, how many major courses do you ideally take relative to your non-major classes?
2-3 major related classes and 1-2 non-major classes.
On average, 5.4 classes with 4.2 in my major. 
Most liberal arts majors typically take up about 35-50% of the total four year schedule. Engineering majors typically take 63%-80% in their major. Those may be the average percentages in your major, but some majors may have more courses in some semesters than others due to prerequisite sequencing (e.g. a math major may take one math course per semester for the first few semesters, but then take two math courses per semester in later semesters).
The remainder of your schedule would be general education requirements and/or free electives (some students use some of these for additional courses in their majors).
The way my four year plan is designed, I have 2-3 courses in my majors (combined) a semester plus 2 academic courses in my minors and 0-1 gen eds. Then I have some ensembles and private lessons for music (minor), so music takes up the most units.
Lol what are these “electives” you speak of?
But actually, I think I have three true electives in my entire four-year plan. The rest of the courses are fulfilling some requirement (although I guess you could count the extra ensembles as electives).
@guineagirl96 - Haha, I have virtually no electives left. I came in with 33 credits from AP exams that counted for most of my general eds and all of my allotted elective space. I think whatever elective room I might have had left I already used up on a whopping two courses (one this semester and one first semester of freshman year.)
Right now I’m looking at 4 major courses and 1 “Honors” course. I tried to pick an interesting honors course that was as radically different from my major (Political Science) as possible. So I settled on a seminar about Biology, lmao.
They are the courses you are taking for your second major and your minor. You are choosing to take the (not required) second major and minor as your electives.
Each semester I have 2-3 classes in my major, 1-2 classes related to but not in my major (My major is civil engineering, so this category encompasses math, physics, etc), and maybe 1 general education class or an elective.