To calculate a test grade percentage, divide the points you earned by the total points possible, then multiply by 100: Percentage = (Points Earned ÷ Points Possible) × 100. A 42 out of 50, for example, works out to (42 ÷ 50) × 100 = 84% — comfortably in B territory on most grading scales.
Why raw points don't tell you much on their own
A test graded "36 out of 40" and one graded "36 out of 60" both show the same raw number, but they represent very different levels of performance — 90% versus 60%. Percentages exist precisely to normalize scores like this so they're comparable across assignments with different point totals, which is why almost every gradebook, syllabus, and transcript ultimately reports grades as percentages or letter grades rather than raw point counts.
Once you have the percentage, the next step is usually mapping it to a letter grade, since that's the form most schools use for GPA calculations, report cards, and transcripts.
Step-by-step: points to percentage to letter grade
- Find your points earned and points possible. These are usually printed directly on a graded test, quiz, or assignment, or listed in your gradebook.
- Divide points earned by points possible, then multiply by 100 to get a percentage.
- Compare the percentage against your school's grading scale to find the corresponding letter grade.
- Optionally, calculate points missed (points possible minus points earned) if you want to know exactly how much room there was for improvement.
Percentage = (Points Earned ÷ Points Possible) × 100
A commonly used percentage-to-letter-grade scale
There's no single grading scale used by every school, but the table below reflects a widely used convention with standard plus/minus increments:
| Letter Grade | Percentage Range |
|---|---|
| A | 93–100% |
| A- | 90–92% |
| B+ | 87–89% |
| B | 83–86% |
| B- | 80–82% |
| C+ | 77–79% |
| C | 73–76% |
| C- | 70–72% |
| D+ | 67–69% |
| D | 60–66% |
| F | 0–59% |
Treat this as a reference point rather than a guarantee. Your instructor's syllabus is the final word — some schools set the passing threshold higher or lower than 60%, some skip plus/minus grading entirely, and some define a separate D- band instead of folding it into a single D range like the one above.
Worked examples
Here's how a handful of common point totals convert, using the scale above:
| Points Earned / Possible | Percentage | Letter Grade |
|---|---|---|
| 45 / 50 | 90% | A- |
| 38 / 40 | 95% | A |
| 72 / 100 | 72% | C- |
| 17 / 20 | 85% | B |
Notice how close some of these are to a cutoff — a 45/50 lands exactly at 90%, the bottom edge of A-. One fewer point earned (44/50 = 88%) would drop it to a B+ instead. This is exactly the kind of edge case worth double-checking by hand, especially if a single assignment could shift your course grade meaningfully.
Points missed matters too
Percentage tells you where you land, but points missed tells you where you lost ground. For a 42/50 test, that's 50 − 42 = 8 points missed. This number is often more actionable than the percentage alone: if you're reviewing a graded test to study for a retake, or asking an instructor to reconsider partial credit on a specific question, knowing exactly how many points are on the table (and on which questions) matters more than the percentage itself.
What this simple calculation doesn't cover
Converting points to a percentage is straightforward, but a few real-world wrinkles sit outside the basic formula:
- Curves. If an instructor curves a test after grading it, the percentage you calculate from raw points won't match your final recorded grade. Our guide on how grade curving works walks through the common curving methods if that applies to you.
- Weighted categories. A single test percentage doesn't tell you your overall course grade if tests, homework, and participation are weighted differently — that requires combining multiple category percentages, not just this one calculation.
- Non-standard scales. Some schools use a different grading scale entirely, including systems where 65% or 70% is the passing threshold rather than 60%. Our letter grade to GPA conversion chart covers how those letter grades then translate into GPA points once you know the scale your school actually uses.
Try it yourself
Rather than doing the division by hand every time a new grade comes back, the Test Grade Calculator converts points earned into a percentage, letter grade, and points missed instantly — just enter what you scored and what the assignment was worth.
