What is a Curved Test Grade?
Sometimes a test is so difficult that the entire class performs poorly. In these cases, teachers may "curve" the grades to adjust the distribution. Here are the three most common methods used:
[Image of bell curve grading distribution]1
The Flat Curve
The teacher adds the same number of points to everyone's score.
Example
Raw: 70%
+ 10 Points
New: 80%
2
The 100% Scale
The highest score in the class becomes 100%. The difference is added to everyone.
Example
Top Score: 88%
Gap: 12 pts
Everyone +12
3
Square Root Curve
Helps lower grades more than higher grades. Formula: √Score × 10.
Example
Raw: 64%
√64 = 8
8 × 10 = 80%
The Basic Formula
Calculating a test score involves a simple percentage formula. You are essentially finding out what "portion" of the test you got right compared to the whole.
Score = (Correct ÷ Total) × 100Or if counting wrong answers:
Score = ((Total - Wrong) ÷ Total) × 100Real World Example
50
Total Questions
5
Wrong Answers
Final Score:
90%(45 Correct)
Test Grading FAQ
Common questions about calculating test scores and understanding grading scales.