Grading in the United States commonly takes on the form of five letter grades (A, B, C, D and F), with A being the highest and F being the lowest. Below is the grading system found to be most commonly used in United States public high schools for the conversion of numeric grades (percentages) to letter grades.
| letter grade | percentage |
|---|---|
A |
90%-100% |
B |
80%-89% |
C |
70%-79% |
D |
60%-69% |
F |
< 60% |
A numeric grade (percentage) expressed as a positive integer \(s \in [0, 100]\).
The letter grade corresponding to \(s\).
87
B