See what each curve changes before applying it to a class.
Both settings stay visible for the comparison table. Capping can create ties and move the mean away from your target.
Common NCES scale. Your class may use different cutoffs.
See this scale ยท Compare cutoffs
A displayed percentage can round up while the unrounded score remains below a cutoff.
Add flat points: add the entered number to every score. Bring the top to 100 by addition: add the gap between the highest score and full credit. Both preserve score gaps until capping changes them.
Scale the top to 100: multiply every score by 100 divided by the highest score. Square root: take the square root of each percentage, then multiply by ten. Check that this is the curve your instructor chose before changing scores.
Target mean: add the difference between the target mean and the current mean. Without capping, the adjusted mean meets the target. With capping, it may not.
The calculations do not tell you which curve is fair or appropriate. Use the rule the instructor or department actually chose. Without capping, some methods can produce scores outside the usual percentage range.
The example scores average 69.375%. Adding ten points gives 79.375%. Scaling the top score instead changes the gaps between students. The table shows ranks and ties for the selected method.
Bell and z-score grading are outside this tool: they need distribution and grade-allocation assumptions that these transformations do not use. For a plain score before any curve, use the easy grader. To change letter boundaries instead, use the grading scale calculator.
