Grade Curve Calculator

How to Use the Grade Curve Calculator

The Grade Curve Calculator is designed to help you understand how your raw score compares to the rest of the class, and how it might be adjusted according to a desired class mean. Follow these steps to use the calculator effectively:

Step 1: Enter Your Raw Score

Begin by entering your raw score in the “Raw Score” field. This is the score you received before any adjustments are made. Ensure that your score is between 0 and 100. The calculator allows precision up to two decimal places.

Step 2: Input the Class Average

Locate the “Class Average” field and input the average score of your class. This number should also be between 0 and 100 to ensure accurate results.

Step 3: Specify the Standard Deviation

Enter the class’s standard deviation in the “Standard Deviation” field. This number measures the amount of variation or dispersion in the student scores. Acceptable input ranges from 0 to 50.

Step 4: Select the Desired Class Mean

Choose your desired mean from the “Desired Class Mean” options, which are represented by different percentage boundaries. You’ll see options like 85% (A/B boundary), 80% (B/C boundary), and 75% (C/D boundary). This choice will determine the target mean for the grade curve.

Step 5: Review the Results

• Z-Score: This value represents the number of standard deviations your score is from the class average. It is calculated using the formula (rawScore – classAverage) / standardDeviation and displayed with two decimal accuracy.
• Curved Score: Your adjusted score based on the desired mean and your Z-Score, calculated as desiredMean + (zScore * standardDeviation). This result reflects potential improvements to your original score.
• Point Adjustment: The difference between your curved score and raw score, displayed for clarity on how much better or worse your score has become after adjustment.
• Percentile Rank: This indicates the percentage of scores lower than your score, calculated using the Z-Score with the formula (0.5 * (1 + erf(zScore/sqrt(2)))) * 100 and presented as a percentage with one decimal precision.

Ensure all inputs are correct and review the results for a comprehensive understanding of where you stand within your class based on the specified grading curve.