First, UC’s calculate their own weighted GPA using only 10-11th grades for the UC a-g course requirements.
As an OOS applicant, only AP/IB or Dual Enrollment courses taken 10-11th grades get the extra weighting in the calculation but HS designated Honors do not. I like to use the RogerHub calculator which will give you the UW UC GPA, the Capped Weighted UC GPA (8 semesters of weighted courses) and the Fully Weighted UC GPA (unlimited semesters of weighted courses).
https://rogerhub.com/gpa-calculator-uc/
Also make sure you meet all the a-g course requirements for the UC’s.
http://admission.universityofcalifornia.edu/freshman/requirements/a-g-requirements/index.html
Be aware that the California UC’s do not offer financial aid to OOS students so expect to pay full fees at $60K/year to attend.
Here is the Freshman profile for UCSB 2017. The 2018 data should be out this August for comparison. Also intended major can make you huge difference on your chances.
UCSB weights academics at around 50% and EC’s/Essays 50%.
Admit rate — Overall 32.8%
Admits: 26,879
Applicants: 81,828
California Residents (% of admits): 69.0%
GPA and test scores of middle 25%-75% students
High School GPA (capped weighted UC GPA): 3.96 - 4.25
ACT Composite Score: 28 - 33
ACT English Language Arts: 26 - 31
SAT Evidence Based Reading & Writing: 610 - 700
SAT Mathematics: 600 - 750
SAT Essay: 15 - 19