Electives and Gpa [on hold]

How do non-weighted electives affect a Gpa?

I was planning on taking three electives and four weighted classes. I am worried, however if this decreases my chances of getting into college; if my non-weighted electives are factored into my Gpa, then it should go down... right? Assuming I got 100% in all the classes and take electives (which I won't :) that would drop my Gpa from 5.0 (no electives) to 4.57. This doesn't take in to account the minimum of required electives at my school.

Also: How does this trade-off of a drop in Gpa vs. extra experience through electives affect my chance of getting accepted into college?

I'm currently thinking of Stanford, Caltech, or Berkeley for a major of Comp Sci or Engineering, though nothing concrete.

Thanks for any advice.