Grade Curve Calculator
Calculate curved exam and assignment grades using standard academic curve methods: Flat Point Boost, Linear Scaling to 100%, Square Root Curve, and Bell Curve (Standard Deviation / Z-Score).
Interactive Grade Curve Calculator Workspace
Single Test Score Curve
Class Batch Scores Roster
Mathematical Formula & Variables
\text{Square Root Curve: } C = \sqrt{R} \times 10, \quad \text{Linear Scale: } C = R \times \left(\frac{100}{Max}\right), \quad \text{Flat Point: } C = R + (100 - Max)Grading curves adjust raw student test scores to normalize exam difficulty. The Square Root curve provides progressive assistance (boosting lower scores more than higher scores). Linear scaling inflates all scores proportionally to a benchmark 100%. Flat point additions give every student an identical score bonus.
Variable Definitions
| Symbol | Description |
|---|---|
| R | Raw test score received by the student (percentage or points) |
| C | Curved final score after applying the selected mathematical curve method |
| Max | Highest raw score achieved in the class (used for linear scaling and flat boosts) |
| Z-Score (Bell Curve) | Number of standard deviations above or below class mean: z = (Score - Mean) / StdDev |
How to Use the Grade Curve Calculator
- Select your grading curve method (Square Root Curve, Flat Point Addition, Linear Scaling to 100%, or Bell Curve Distribution).
- For single student calculations, enter the raw score and the highest class score or test max points.
- For full class batch curving, paste a list of raw test scores (separated by commas or new lines).
- Review original vs. curved scores, class mean shift, standard deviation, and letter grade adjustments.
- Export or copy the curved grade roster with letter grade assignments (A, B, C, D, F).
Exam Score Curve Comparison Example
Scenario Context: On a challenging college chemistry midterm, the top student scored 85 out of 100, the class average was 58, and a student scored a raw 64. Calculate the curved score using: (1) Square Root Curve, (2) Flat Point Curve to 100%, and (3) Linear Scaling to 100%.
Frequently Asked Questions
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