A standard C average would equate to a 2.0 grade point average, or GPA. An A average would be a perfect 4.0, and each grade drop is equivalent to a 1.0 drop on the GPA scale. This means a B average would be a 3.0, and a D average would be a 1.0.
A standard GPA scale tops out at 4.0, but some schools allow students to go above this if they take advanced placement classes or college classes for both high school and college credit. It's also important to note whether the school uses plus and minus grades. If so, the range for a C average can be from 1.7 to 2.3.