How Do I Turn Rubric Marks Into Fair A to E Grades?

Published on 23 October 2026

To turn rubric marks into fair A to E grades, add up the marks, convert the total to a proportion of the marks available, and map that proportion onto grade cut-offs you have decided in advance. Then look again at every piece of work sitting near a boundary and ask whether the grade matches your description of A, B, C, D or E work. The arithmetic gives consistency, and your professional judgement gives accuracy.

Why is converting marks to grades harder than it looks?

A rubric measures parts; a grade describes the whole. A student can collect solid marks on structure, vocabulary and spelling while never really answering the question. Another can write an insightful response with a messy final paragraph. If you only add points, the first student may outscore the second, which rarely matches what you would say about their work.

There is also drift. Over a long night of marking, the same 14 out of 20 can start to feel like a B in one essay and a C in the next.

How should I design a rubric that maps cleanly to A to E?

Start from the grade descriptors, not the other way round. Ask what distinguishes a C response from a B response in this task, then build criteria that capture that difference.

• Use four or five criteria, each tied to something you taught.
• Weight criteria by importance. If analysis is the heart of the task, give it more marks than presentation.
• Write a short descriptor for the top and middle of each criterion, using words students understand.
• Decide your cut-offs before you mark, and write them on the rubric so students can see them.

A common approach is evenly spaced bands, but you can set your own. The key is deciding before you read the first piece, not after.

What about the borderline pieces?

Borderline work is where fairness is won or lost. A practical routine:

• Sort your marked work by total and pull out anything within a few marks of a cut-off.
• Read those pieces side by side against your grade descriptors.
• Ask one question: does this piece look more like the grade above or the grade below?
• Adjust where needed and note a brief reason, so you can explain it to a student or a parent.

If your faculty moderates together, bring two or three borderline samples rather than your best and worst. They produce the most useful discussion.

How do I explain a grade to a student?

Point to the rubric. "You earned strong marks for evidence, but your analysis stays at description, which is why this sits at C rather than B." When the grade links clearly to criteria, students argue less and improve more. Give one specific next step for the criterion that held them back.

Can AI apply the conversion consistently?

AI can help with the part humans find hardest to keep steady across thirty pieces: applying the same rubric the same way every time. Korektor is a web app that marks written work against your criteria and points, then converts the total roughly proportionally to an A to E grade, with C as the pass. You review every result and can change any grade, so the borderline judgement stays with you.

Each result includes a score and comment for each criterion, which makes the borderline check faster: you can see at a glance which criterion pulled a piece below a cut-off.

How do I set up A to E marking in Korektor?

1. Create an assignment from a template (science report, composition or argumentative essay) or from scratch, with the task, word range and deadline.
2. Enter your criteria with points, weighted the way you want. Paste your grade descriptors into the free-text instructions for the grader.
3. Choose strictness (lenient, balanced or demanding) and feedback tone (encouraging, neutral or direct).
4. Choose what the AI checks, such as spelling and punctuation, subject vocabulary, sources and comments on the text, and decide whether students see their grade.
5. Share the link. Students type their name, need no account, and upload a Word document, PDF, PowerPoint, OpenDocument file, plain text or up to 8 photos of handwritten work.
6. After about 20 to 60 seconds per piece, open "received papers", sort out the borderline cases and adjust any grade you disagree with.

Should students see the grade straight away?

Not always. Some teachers prefer students to read the feedback first and see the grade later, so they engage with the comments instead of the letter. Korektor lets you hide the grade from students while still showing them the criterion comments, strengths and things to improve. The estimate of AI-written text is visible only to you by default.

How much does it cost?

The first 3 markings are free without an account, and a free account adds 3 more. After that, packs are 30 markings for 5 euros, 100 for 14 euros or 300 for 36 euros, and they do not expire.

If your next assessment task is coming up, write your cut-offs on the rubric first, then try marking a handful of pieces with Korektor and compare the grades with your own.

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