Courses at Stanford are commonly 3 units?

I am a parent of a prospective student and I want to know if most courses are worth 3 units or if that is common because I am trying to estimate the amount of courses a student needs to take in order to fulfill the 180 units for my son.

It is like other universities where some classes such as chemistry with a lab or calculus may be 5 units.

They vary a lot. People tend to take an average of 4 classes a quarter. But it varies wildly. I’m in three classes right now, each one five units. Last quarter I took four classes, two 3 one 5 and one 7. They have a lot of sample four year plans online that give a really good idea!

A student needs to average 15 unites per quarter (or 45 units per year) to graduate in four years. As the previous poster said, the number of units for a class varies a lot. My ds has taken anywhere from 14 units to 19 units in a quarter. That has been anywhere from 3 to five (maybe even six?) courses. There are some 1 unit courses as well. Most (I believe) are between three and five units each.

It can go from 1 to 5. 1 might be a seminar or research credit. You can have AP or IB credits to fulfill the 180 for graduation.