Letter Grade Calculator Formula
Understand the math behind the letter grade calculator. Each variable explained with a worked example.
Formulas Used
Grade Points (4.0 Scale)
grade_points = percentage >= 93 ? 4.0 : (percentage >= 90 ? 3.7 : (percentage >= 87 ? 3.3 : (percentage >= 83 ? 3.0 : (percentage >= 80 ? 2.7 : (percentage >= 77 ? 2.3 : (percentage >= 73 ? 2.0 : (percentage >= 70 ? 1.7 : (percentage >= 67 ? 1.3 : (percentage >= 60 ? 1.0 : 0)))))))))Pass or Fail
pass_fail = percentage >= 60 ? 1 : 01 = Pass, 0 = Fail
Percentage
percentage_out = percentageVariables
| Variable | Description | Default |
|---|---|---|
percentage | Grade Percentage(%) | 87 |
How It Works
How to Convert Percentage to Letter Grade
The standard grading scale maps percentage ranges to letter grades.
Standard Scale
Worked Example
A student scores 87% in a course.
percentage = 87
- 01Score: 87%
- 0287% falls in the 87-89 range
- 03Letter grade: B+
- 04Grade points: 3.3
Frequently Asked Questions
Do all schools use the same grading scale?
No. While this scale is common in the US, some schools use different cutoffs. Always check your institution's specific policy.
What is the minimum passing grade?
In most US institutions, a D (60%) is technically passing, but many programs require a C (73%) or higher in major courses.
How do plus and minus grades affect GPA?
Plus grades add 0.3 points (B+ = 3.3 vs B = 3.0) and minus grades subtract 0.3 (B- = 2.7). This can meaningfully affect your GPA.
Ready to run the numbers?
Open Letter Grade Calculator