A 3.5 GPA is equivalent to a B+ letter grade or 87-90% . To convert a 3.5 GPA to a percentage, we need to know the grading scale. For example, on a 4.0 grading scale, a 3.5 GPA is equivalent to 87.5% . On a 5.0 grading scale, a 3.5 GPA is equivalent to 70% . To convert a GPA to a percentage on a 10-point scale, we can use the formula GPA = (percentage/100) x 10, or GPA = percentage divided by 10. Therefore, a 3.5 GPA would be equivalent to 88% on a 10-point scale. A 3.5 GPA is considered a good GPA, as it is above the national average of 3.0. It is also a competitive GPA for many selective universities.