Have you decided to assess your elementary or middle school child using letter grades—or does your state requires grading before high school?

Maybe you are homeschooling a high schooler and need to understand how those pesky letters work. Either way (or if you’re just here because you’re curious), we want to help you feel confident in grading your student.

Letter grades are a bit complicated. In order to use them, you’ll need to get the hang of a few concepts.

Percentages

Letter grades are based on percentages. Any time you grade your student’s work, you’ll first come up with a percentage grade. The simplest way to determine a percentage grade is to count the number of questions your student answered correctly, divide them the by total number of questions in the assignment, and multiply the result by 100.

Suppose your student took a math test with 20 questions and answered 17 questions correctly. Here is how you would calculate the percentage grade:

17 ÷ 20 = 0.85
0.85 × 100 = 85%

Grading scale

Next, you’ll need a grading scale to convert the percentage grade into a letter grade. A grading scale assigns a letter grade to each range of percentage grades. For example, a grading scale might say that a percentage grade from 91% to 100% is the equivalent of the letter grade A. Now, it’s important to remember that there is no one right grading scale. Different teachers use different grading scales. Here are two possible grading scales, and they are both OK to use—or you could use a different one entirely!

90–100% = A93–100% = A
80–89% = B86–92% = B
70–79% = C78–85% = C
60–69% = D70–77% = D
0–59% = F0–69% = F

According to the grading scale on the left, the hypothetical math grade arrived at above would convert to a B. But if we use the grading scale on the right, the student would receive a C.

As the homeschool parent, you get to decide what grading scale you’ll use (in most cases). If you plan to send your child to a traditional school at some point, it is helpful to ask that school what their grading scale is so that your child’s homeschool grades will be consistent with the school’s grading approach.

Weighting

But what if you’re grading an assignment where you want some of the answers to be worth more of the final grade than others? Great question—and this is where weighting comes in.

Let’s go back to that hypothetical math test. Suppose that, out of the 20 questions on it, 15 were simple calculation problems and 5 were word problems. As the homeschooling parent, you’ve decided that the 15 simpler problems should be worth 50% of the test grade, and the word problems should be worth 50%. Your child answered 13 of the 15 simpler problems correctly, and 4 of the 5 word problems correctly.

So . . . here’s what you do:

  1. Figure out the percentage grade for each type of problem (but don’t worry about multiplying the result by 100).
    13 ÷ 15 = 0.8674 ÷ 5 = 0.8
  2. Multiply each grade by the weight you assigned to it. Since each type of problem is worth 50% of the final grade, you’ll multiply each individual grade by
    0.867 × 0.5 = 0.430.8 × 0.5 = 0.4
  3. Add the two grades together, multiply by 100, and voila—the final test grade! (Of course, the grade isn’t really final until you use the grading scale to find the applicable letter grade, but you get the idea.)
    0.43 + 0.4 = 0.830.83 × 100 = 83%

That sounds really complicated!

If developing your own grading system for your student’s work is beyond what you want to do, you have plenty of options. Many textbooks are accompanied by a teacher’s guide that provides the grading system for you. All you do is follow the guide’s instructions. Or you could choose to have your child take online or DVD-based courses, which may include grading guidelines or might actually be graded for you (imagine that!). Hybrid schools also provide grading help.

And don’t forget that for most elementary and middle school students, grading is not required (but always check your state law to be sure).

By the way, if you’re looking for more in-depth grading help, we suggest the short series on high school grading below.