A 68 percent grade is equivalent to a D+ letter grade. This means that a score of 68 out of 100 on a test, assignment, or class is below average or less than satisfactory performance. A 68 percent grade is also in the range of 67-69.9 percent, which is a D+ on the grade scale table. In Minneota Public Schools, a 68-69 percent grade is equivalent to a D+ .