Methods of Calculating Grades in SBG

A barn with windmills on a prairie.

I'm prepping a full-day workshop on standards based grading for about 20 teachers in a couple weeks. One major part of the day will be centered on converting a SBG report to a 100-point scale letter grade, mostly because we just have to.

Here are some of the methods I've come across, which have all (in one way or another) informed my own method, which is last in this post.

Equalized Weighting

I saw this calculation method first from Frank Noschese on his KISSBG blog post. He glances over it in the post body, but the comments below get into some of the details. Here's the formula:

50 + 50 * (earned/total)

At first, the additional 50 points added in look like a bonus, which feels weird. In reality, this wipes out the 0-50 F range. Now, each letter grade rougly corresponds to a 10-point spread:

  • F: 50 - 60
  • D: 61 - 70
  • C: 71 - 80
  • B: 81 - 90
  • A: 91 - 100

It's an equivicator, not a bonus.

Reflective Grading

Shifting away from assigning arbitrary points is a big piece of standards-based grading. Laura Gibbs, Kathryn Byars and Ken Bauer are the three names that jumped out in this region. Feedback is the main driver. Work is given feedback and only feedback. The focus between teacher and student is on demonstration, not on points or numbers.

For assessment, students reflect on and provide evidence of proficiency on each standard. Laura, Kathryn, and Ken all did this differently, but the main flavor is the same. Take a look at Kathryn's helpful Google slides, Laura's deep-dive book chapter and Ken's various blog posts. This is by far the most flexible, fuzzy, and subjective method of reporting.

Standard Purism

The most "pure" method of standards-based grading removes all items from the gradebook except for the standards. The methods of grading these varies. Some use a straight average of binary items (pass/fail). Others put each standards on some kind of rubric scale and give an average.

The main benefit of this structure is that practice work (homework, classwork, etc) is excluded. If a student forgets or decides not to do an assignment, their grade is not affected because it is practice.

On the other hand, this opens the door for assignments to be completely optional. This is a detriment, in my opinion, because students may not have the self-awareness or diligence to do independent work otherwise. Additionally, if a student skips a test or quiz because it doesn't go in the gradebook, it can set up an awkward situation where a student is racing to prove standards at the end of the year.

Some kind of blend

I ended up blending several of these ideas into a system I like. I used components of KISSBG (binary yes/no for standards) with a weighted course average to calculate the final grade.

Category Weight
Classwork 20%
Standards 80%

In my gradebook, any classwork/practice was lumped together into one category. Homework, tests, quizzes, etc, all contributed to 20% of the total course grade.

Standards were individual assignments worth one point. They were assessed over time on a four-point rubric:

Description Score
Exceeds Expectations 4
Meets Expectations 3
Approaches Expectations 2
Does Not Meet Expectations 1
No evidence 0

The cutoff for toggling a 1/1 in the gradebook was a 3. This meant they demonstrated proficiency in the concept in that situation. A 4 was given if the student could connect different related ideas...showing the relationships between standards.

Rubrics were used on every assignment and that aggregate score was used to determine the gradebook 1 or 0. Over time, patterns emerged and students were able to track their growth/decline in Canvas (more on that another time). I rarely graded Classwork assignments in depth...if it was turned in, I often gave full credit just for having it done. The rubric feedback was the important piece and I tried to put the focus on learning from those pieces.


Is ther a best method? I don't think so. It really depends on your group of students and situational context. In 2012, I used a more reflective approach. In 2016, I was using more the 80/20 split with some reflection thrown in. Both were equally valid and I felt good about the grades I ended up reporting.

What others would you suggest? Leave a comment below.