Taking 20 units at UC Berkeley

I am a Freshmen considering the following classes for next semester:
Math 1A
Math adjunct class
Econ 2
Colwrit R1A
Chinese 1A

However, I am a bit worried as the course load would be 20 units.
Is this too much? Or is it doable since all of these classes are lower division classes?

Hard to say without knowing how you did in HS and in your first semester.

Since you are going through your freshman year Fall Semester, you should have a good idea of the pace and work load at Cal. You might want to: 1) sign up for the Spring Semester classes anyway; 2) see how your grades are after the Fall semester of freshman year is completed; and 3) in the Spring Semester, sit in on the classes you enrolled in (20 units) and decided whether you can handle the 20 units or not. If you decide to drop a class, make sure you drop before the deadlines.

It is doable if you can handle the work load and manage your time well.

Doable if you took calc in high school. Really, still doable if you didn’t. Heard the 4 writing series was easier.
I feel like if you are considering 20 units, 20 units will probably be fine. Make sure you organize what phase you’re going to enroll in each of them.
I have no experience with language classes here, though, so I don’t know how much work it’ll be.
Writing will be a few essays, probably about 1 every other week.
Math will be normal math homework.
Econ has some reading that I did but people generally don’t do. But Mankiw is a pretty easy read compared to some other more dry books.

If the OP has not fulfilled the entry level writing requirement, s/he needs to take College Writing R1A rather than R4A.

With respect to College Writing R1A, the instructors’ themes are listed at https://writing.berkeley.edu/course/accelerated-reading-and-composition-12 , so try to choose one with a theme of interest.

As far as difficulty goes, what is your current course load and how well are you doing in each course?

Difficulty of Math 1A will depend on how strong your algebra/trigonometry/precalculus foundation is.

College Writing R1A should be expected to be a good deal of work at 6 units, especially since placement in that course means that your writing skills are below the entry level writing requirement level.

Foreign language courses in college are much more intense and faster paced than in high school. Chinese language courses at UCB do have separate courses for heritage speakers (1X and 1Y), with 1A specifically for non-heritage speakers (i.e. those who did not grow up with Chinese speaking parents or in a Chinese speaking environment).

Cal is full of top HS students who were absolutely demolished their freshman years, so I think your current first semester is a better barometer of how many units you can handle. Anyone would find 20 units a challenge, not just from a performance perspective, but from a sanity perspective. Are you in a hurry to get out in less than 4 years? Or are you considering double majoring or minoring? Loading yourself up will leave yourself little time for research, clubs, activities or socializing. Sometimes, it’s those extracurriculars that catch the eye of an internship program or recruiter.

Sign up for what you want, but be mentally prepared to drop something if you find yourself overwhelmed. It’s good to know your limits - you may figure that out sooner than later.