A 91 is an A. On the standard grading scale used by most American schools, an A covers 90 to 100 percent, and a B covers 80 to 89 percent. Your 91 lands comfortably in A territory.
How the Standard Grading Scale Works
Most U.S. high schools and many colleges use a straightforward 10-point scale to convert percentage grades into letter grades:
- A: 90–100
- B: 80–89
- C: 70–79
- D: 60–69
- F: Below 60
Under this system, a 91 is a solid A. On a 4.0 GPA scale, an A is worth 4.0 points per class, according to the College Board’s standard conversion.
What Changes With Plus and Minus Grades
Some schools break letter grades into finer slices using plus and minus designations. When they do, a 91 typically falls into the A-minus range rather than a straight A. A common plus/minus scale looks like this:
- A: 94–100
- A-: 90–93
- B+: 87–89
- B: 83–86
Under this version, your 91 is still in the A family, just with a minus attached. An A-minus usually carries a GPA value of 3.7 instead of the full 4.0. That distinction matters if you’re tracking your GPA closely, but it’s still well above B-plus range.
Why Your School’s Scale Is the One That Matters
There is no single universal grading scale. Individual teachers, departments, and institutions set their own cutoffs. Some professors place the A threshold at 92 or even 93, which would push a 91 into B-plus territory. Others curve grades so the cutoffs shift based on class performance. The only way to know for sure is to check the syllabus or grading policy for your specific course.
If you’re looking at a grade on a report card or transcript, the letter grade your school assigned is the official one. If you’re estimating where you stand mid-semester, use the scale your instructor listed in the syllabus. When no scale is specified, the standard 10-point version applies, and a 91 is an A.