Most colleges and high schools use a four-point scale for calculating GPA, making the highest GPA a 4.0. On this scale, an A is four points, a B is three points, a C is two points and a D is one point.
Some schools use weighted grades for honors or Advanced Placement (AP) level courses. These weighted grades are based on a 5-point scale, where an A is five points, a B four points, a C three points and a D is one point. Thus, if a student took all AP or honors classes and got all A's, they could have a 5.0 GPA. Some colleges do not accept a weighted GPA, whereas others will.