Two weighting conventions for honors
Most US high schools weight honors courses at +0.5. An A in Honors English earns 4.5 grade points. A B+ in Honors Chemistry earns 3.8.
UC and some other systems weight UC-approved honors at +1.0, the same as AP and IB. If you are calculating for a UC application, use /uc instead, which also handles the 8-semester cap.
Not every "honors" course earns the bonus
Schools and admissions systems define honors specifically. Your high school may call a course honors, but UC or your weighted scale may not recognize it. Check with your counselor or the UC Doorways system before relying on the bonus.