From Rubric To Percentage

In a stack of papers called Grading.

  • Sep
  • 21
  • 2008

How can I take the scores from my assessment on a six-point rubric and turn them into a percentage? 3, 3, 4, 4: that doesn’t convert very well to a score out of one hundred. I have this problem every year, with varying and inconsistent solutions. This time, I’ve set Excel in place to keep my evaluations constant.

Writing Scoresheet for writing assignment #1 in 2008-09If you want to skip the discussion of how I got here, I understand. Here’s the spreadsheet and the rubric. Take a look at them both and get back to me with any questions or comments. If you’re curious how I worked this out, read on, my friend.


Some rows of the rubric are more important than others. Since I know what each row on the rubric should be worth in the final score, it’s about dividing the score I want each row to be worth into six. I cranked out some numbers and figured out the computations for my scale:

30 points
30 points
20 points
10 points
10 points
Rubric score * 5 Rubric score * 5 Rubric score * 3.34 Rubric score * 1.67 10-point scale provided

Not Equal

A six-point rubric works like this (at least, it does to me):

In My Head:
6/6 5/6 4/6 3/6 2/6
100% 85% 75% 65% 50%
The Trouble:
6/6 5/6 4/6 3/6 2/6
100% 83% 67% 50% 33%

As the rubric score drops, a certain number must be added to the sum in order to keep to the percentages. Four out of six equals 67%, not quite the grade of C I have in mind. Five out of six equals 83%, close to, but not quite, the grade of B I have in mind. I figured out how to manage that (in this case, N2 is the cell with the rubric score):

=(N2*5)+(IF(N2>5, "0", IF(N2>4, ".5", IF(N2>3, "2.5", IF(N2>2, "4.5", "5" )))))


As I read, I focus on comments. After I read, I focus on the grade. Matching up the best description of the writing to the score on the rubric, I enter scores and let Excel do the math. I keep this all electronic, which means printing out somewhere near ten pages and making good friends with the paper cutter and stapler each essay. But all that is probably faster than the bog of adding numbers with a calculator and entering scores onto each paper. Anything that gets me moving to the next one faster, while still giving time to the current one, is a good thing.

On the scoresheet I’ll print out (see image above), the Writing Percentage is the grade on the paper without the score for MLA format figured in. It’s my actual assessment of their writing skill, something into which the ability to format a paper doesn’t/shouldn’t factor. But since MLA format is a requirement of the writing, the Final score is the percentage earned on the assignment. In a nod to Dan’s method of assessment, I’ll be entering each score into the gradebook separately so that we can see development on each area of the rubric across the school year. This should give the students an idea where they need to spend time and me an idea what to review and re-teach.


1. Ben says:

[9/22/2008 - 4:19 pm]

I ran across a similar situation earlier this year on rubrics other teachers had created to grade student lab reports. To circumvent the weighting problem you mention above, I rewrote the rubric, putting in actual point values instead of just the 1, 2, 3, 4, etc. However, I’m guessing the writing rubric is something that’s required by your school or district to assess student writing? In that case I think you’ve found a pretty good solution. It obviously took a bit of upfront work, but it seems to do the job well.

If only you didn’t have to mess with the paper cutter & stapler bit. When I’ve used rubrics in Excel I’d email each student their rubric to their school account. Not sure if that’s an option for you, but it worked quite well for me. Student would often email me back with questions on what they could’ve improved upon that they never would’ve asked in class.

2. Todd says:

[9/22/2008 - 6:05 pm]

Really, it’s that the rubric matches the SAT and college entrance exam rubrics. Also, my head is calibrated to it (it was, at one time, mandated by the district).

Email is not a reliable method of communication here, both because some don’t have it and others wouldn’t read it if I sent it there. I don’t mind the work because I think it’s worth it (just did it today with 5th period). And I can leave the stapler out of it, simply having students staple it to the page themselves.

The original paper, along with my scoresheet, is their pass to rewrite for a higher grade. If they lose either of those things, they cannot rewrite. I didn’t pass around staplers today, but I will in my other periods.

3. Kim Moore says:

[9/23/2008 - 2:47 pm]

enjoyed this, helpful in my current study of rubrics
in the adult classroom
thank you