Can someone explain weighting to me?

<p>My school does A (94-100) as a 4, B+ (90-93) as a 3.5, B (84-89) as a 3.0, etc. with a 0.5 boost if the class is AP. No boost for honors.</p>

<p>What is the standard system of weighting? I know some schools go over 4.5, what is their weighting system? Do colleges recalculate your GPA according to their own systems?</p>

<p>should have said *county, not school</p>