they do use their own method, but you mentioned you wanted to get an idea of what your gpa would be. make an excel spreadsheet and figure it out (A+ = 4.33, A = 4.0, A- = 3.67, B+ = 3.33, etc). i dunno what a W would be, i presumed it would be counted as 0 for gpa points, but i was stoned for making a comment like that so I will stay far, far away from that subject.