AP Graduate early

Hi, do many/most students graduate early because of AP credits? Are there any problems with getting lots of AP credit in L&S?

thanks

UC gives credit units for AP scores as described here:
http://admission.universityofcalifornia.edu/counselors/exam-credit/ap-credits/
Note: multiply by 2/3 for Berkeley and Merced, since the given numbers are for quarter units. Credit units may be applied to the 120 units needed to graduate, unless cancelled by taking a duplicating course.

Subject credit for AP scores at UCB L&S is limited:
http://admission.universityofcalifornia.edu/counselors/exam-credit/ap-credits/berkeley/index.html
Note that the L&S 7-course breadth requirement cannot be fulfilled with AP credit.

In addition, some AP scores may be used to fulfill requirements for some L&S majors. You need to check the major department web site for its AP score policy. Examples:
https://math.berkeley.edu/courses/choosing/ap-exams
https://www.econ.berkeley.edu/undergrad/prospective/freshmen
http://psychology.berkeley.edu/students/undergraduate-program/lower-division-requirements-applicable-freshman-and-transfer-students
http://ib.berkeley.edu/undergrad/major/freshman.php
https://mcb.berkeley.edu/undergrad/advising/advising-office/freshmen#13

Thanks, but my question is one of actual practice. From the website it looks like it is easy to do, but if so, why don’t lots of students do it. For example, the UC Davis site looks similar, but it turns out that that the AP credits are useless if you are in engineering because of all the requirements, according to my friend there.

Maybe because they want to (re)take the equivalent classes of the AP credits to enforce the knowledge.
My D graduated EECS in 3 years. She was granted 21 (or 27, I don’t remember the exact number) AP units. She also had about 30 units of college-level (above AP level) math and physics from Stanford EPGY, which were evaluated to comparable classes by UCB Math Dept. and Physics Dept… But CoE didn’t allow those units. She however could use those to petition to take more advanced Math and Physics classes instead of the basic required classes.