How are API scores calculated?

For anyone who is curious about how API scores for schools are calculated, I ran across this description from the CA department of education.

Most of us look at API scores for 2 reasons:

1) To see how highly ranked our kids' schools are
2) To see how our home values will be affected by the quality of the schools around our homes

As I've said before, schools with good API scores provide a great foundation for our kids - but these scores do NOT guarantee our kids' acceptance into the Harvards and Stanfords of the world. In all schools - high-API ones and low-API ones, there are always going to be a 'bell-shaped' distribution of high achievers and low achievers. It is my belief that it is mostly up to the parents to teach, mold, and motivate their own kids to be successful.