GPA is generally on a 4-point scale.
How percentage grades match to grades and grade points is not necessarily the same between schools. You should probably ask your school. Of course, not all schools even relate to GPA’s.
However, often the scale is something like:
90–100 A
80–89 B
70–79 C
60–69 D
So one might read your grades as A, A-, D+, A-, B+, A
Plugging those into the link @johnpowell provided, and assuming all classes have the same weight, I get a GPA of 3.333. (i.e. a B+ average)