Enter the maximum grade score achieved on the test and any individual test score into the calculator to scale/curve the individual grade.

Scaling Grades Formula

The following formula is used in scaling and curving grades of a test.

SG = OG * 100/MG

  • Where SG is the curved grade (%)
  • OG is the original grade (%)
  • MG is the maximum grade scored on the test (%)

Scaling Grades Definition

Scaling a grade, or curving a grade as it’s often referred to, is the process of changing the scores of a test to represent the performance of the overall class on a 100 point scale.

This most often means that the highest grade scored is scaled to 100, and any score under that is scaled based on that highest grade.

Why do teaches curve grades?

Teachers curve grades because they want to increase the overall test grade average of the test. There can be several reasons for this, one of them being if a test they design ends up being too difficult and the whole class gets bad grades, they want those grades brought up so the students aren’t failing.

How much do teachers curve grades?

Teachers curve grades based on several factors, but typically teachers want the average grade of the class to be in a certain range. If they accidentally make one test too difficult they don’t want that to mess up the entire average of the class.

Is grading on a curve good or bad?

Grading on a curve can be both good and bad. It can be good because it can help fix a student’s grade when a teacher did not prepare a proper test or teach a subject well enough.

Students should not fail classes because of a teacher’s failure to design a proper test.

Curving can also be bad for several reasons. One of those is that the student that scores the highest typically benefits the least since they are capped at 100%. Second, it can hide the failures of the teachers when they don’t teach well enough,

How to curve a grade?

Example Problem:

First, determine the maximum score achieve on the test. For this example, the highest score achieved was 95%.

Next, determine the original pre-scaled grade of any individual student. In this case, the student being looked at had an original score of 80%.

Finally, calculate the students new curved grade using the formula above:

SG = OG * 100/MG

SG = 80 * 100/95

SG = 84.21%