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A Beginner's Guide to Figuring Your Grades

by Scott Mandel, Ph.D.

A new teacher at my school had a lot of trouble because she flunked an unusual number of middle school students. However, these weren't "bad" kids—in fact, her class was usually the only class in which these students received a poor grade. When I sat with her, she showed me a typical student's test grades: 25, 80, 40, 95, 90. She then did a straight average of these grades to determine a final grade. Now, even though this student had received 2 A's, 1 B, and 2 F's, the final grade given by the teacher was a 66%, "D." The student and her parents could not understand how this was possible.
One of the skills that are usually not taught in teacher education programs is "how to grade." Unfortunately, new teachers are expected to "pick this up on their own." However, it is also an area where new teachers are closely scrutinized by administrators and parents. The following are some basic tips that new teachers can use to guide them as they begin to develop their own grading systems.

The Basic Mind-Set

A teacher should always "role-play" as he/she formulates the grades. I role-play that every parent of a negative grade is going to come in to complain. I then ask myself if I can objectively justify the grade. If I can, if the numbers add up correctly so that it makes sense, then the grade stands and I go on.

Get a Calculator

I know that this sounds very basic, but a calculator helps make your grading much more objective, more "defendable" (see the section directly above), and easier to figure.

Use a System of 100 (a percentage system)

Always convert all grades and numbers to a system of 100. It will not only be easier for you to figure out overall grades, but it will simplify your explanations to parents and administrators if they can see your grades in terms of percents.


You gave a quiz worth 30 points. The student received 27 points. 27/30 gives a percentage of 90%. A score of "90" is written in your grade book.

Failing Grades Below "50" Always Get Marked as a Score of "50"

This was where the teacher in the anecdote above made her mistake. By averaging in any failing mark, as is, you unfairly weigh the mark in the overall grade. For instance, if a student takes 2 tests, scores a "0" on one (F) and a "100" on the other (A+) it would be logical that an "A" and "F" average out to a "C." However, by purely using their numerical values, the student's average with these two tests becomes a "50," which usually translates into an "F"! Let's once again look at the example of the new teacher above.


The student in the example received: 25, 80, 40, 95, 90. Average = 66%, Grade = D
The student's grades should be converted to 50, 80, 50, 95, 90. Average = 73%, Grade = C, which is a better representation of grades of A, A-, B-, F, F.

Convert Letter Grades to Numbers

It is always easier to average numbers; it is always more understandable for other adults to see a percentage/number total. There are two ways to work with the numbers, a percentage system (based on 100) and a grade-point system (based on 4.0 points, as done in high school and college). Here are how they work:

Percentage System

All letter grades are converted to a numerical equivalent, equi-spaced from each other, based on a 100 point system. Then they are averaged as you would with other grades. Here is a chart you can use:

A++ = 100 (perfect paper with extra-credit)
A+ = 98
A = 95
A- = 92
B+ = 88
B = 85
B- = 82
C+ = 78
C = 75
C- = 72
D+ = 68
D = 65
D- = 62
F = 55

Grade Point System

All letter grades are converted to a grade equivalent, based on the 4.0 system. Then they are averaged and converted back into a letter grade (as is done in high school and college GPA's). Here is a chart you can use:

A+ = 4.3
A = 4.0
A- = 3.7
B+ = 3.3
B = 3.0
B- = 2.7
C+ = 2.3
C = 2.0
C- = 1.7
D+ = 1.3
D = 1.0
D- = 0.7
F = 0.0

After the point values are averaged, they are converted back into a letter grade. Here is a chart you can use ("borderline" grades are of course up to the discretion of the teacher):

4.0-4.3 = A+
3.7-4.0 = A
3.5-3.7 = A-
3.3-3.5 = B+
2.7-3.3 = B
2.5-2.7 = B-
2.3-2.5 = C+
1.7-2.3 = C
1.5-1.7 = C-
1.3-1.5 = D+
0.7-1.3 = D
0.5-0.7 = D-
0.0-0.5 = F

Establish Your Final Grading Formula Numerically

Determine ahead of time the weight given to each of the sections of your grade book. Here's an example:

Tests 50%
Quizzes 25%
Project 25%

Using these percentages, this is how I would figure out a student's grade:

Tests = 86% = 86 X 2 = 172 (Tests are worth twice as much as the other two, therefore, doubled)
Quizzes = 79% = 79 X 1 = 79
Project = 92% = 92 X 1 = 92
172 + 79 + 92 = 343 divided by 4 (4 parts, Tests twice, Quizzes, Project) = 85.75 = 86 = "B"

Here's a much more complicated example, using possible percentages and an imaginary student's grades:

Tests 30%: student score of 80% = 80 X 3 parts = 240
Quizzes 30%: student score of 90% = 90 X 3 parts = 270
Project 20%: student score of 75% = 75 X 2 parts = 150
Homework 10%: student score of A- = 92% = 92 X 1 part = 92
Class Participation 10%: student score of C = 75% = 75 X 1 part = 75
Total = 240 + 270 + 150 + 92 + 75 = 827 divided by 10 parts = 82.7 = 83 = "B"

It may be a little extra work, but it will go fast once you get used to it. More important it will be fair and defendable! And those are the two most important components to grading, especially for new teachers!

©2004 Scott Mandel

About the Author: In his more than 25 years as an educator, Scott Mandel has served as a teacher, an administrator, and an in-service leader. Currently, he teaches English and history at the Pacoima Middle School Television, Theatre, and Fine Arts Magnet in Los Angeles. He received his Ph.D. in Curriculum and Instruction from the University of Southern California; his current areas of professional specialization include classroom management, teaching methodology, and using the Internet in educational settings. A National Board Certified teacher, Scott is the author of four previous books as well as the founder and developer of Teachers Helping Teachers, a Web site for educators. Teachers Helping Teachers has been offering lesson plans, educational links, and inspiration since 1995.