How to Calculate a Grade Percentage
Last updated: October 11, 2026
A grade percentage tells you what share of the available points you earned. The formula is the same for a single assignment or a whole class.
The formula
Percentage = points earned ÷ points possible × 100
- 17 out of 20: 17 ÷ 20 = 0.85, so 85%
- 43 out of 55: 43 ÷ 55 = 0.782, so 78.2%
Points needed for a target percentage
To find how many points get you a target, multiply the target by the points possible. For 90% on a 60-point assignment, 0.90 × 60 = 54 points.
Percentage to letter grade
A common scale is 90–100% for an A, 80–89% for a B, 70–79% for a C, 60–69% for a D and below 60% for an F. Schools differ, so check yours. The letter grade scale has the full chart with plus and minus grades.
Score percentage and weight are different
The percentage you scored on one assignment is not how much that assignment is worth. A 100% on a small quiz moves your class grade much less than an 80% on a final exam.
Let the table do it
Paste your gradebook into Grade Calculator and the table fills in on its own, with your class percentage and letter grade shown as you change scores.