To convert a raw numeric grade to a letter grade, first turn it into a percentage by dividing the score by the maximum possible points and multiplying by 100, then apply your school's standard percentage-to-letter-grade cutoffs — for example, 17 out of 20 equals 85%, which typically falls in the B or B+ range on a common US letter-grade scale.
Why raw numeric grades need an extra step
A percentage grade (like "88%") is already expressed out of 100, so it maps directly onto a percentage-to-letter chart. A raw numeric grade — common on assignments scored out of 20, 10, 50, or some other total — first needs to be converted into that same 0–100 frame before a standard letter-grade chart can be applied. Skipping this step, or misreading the maximum possible score, is one of the most common sources of grading confusion, especially when different assignments or courses use different point totals.
Percentage = (Raw Score ÷ Maximum Possible Score) × 100
Step-by-step conversion
- Confirm the maximum possible score. This should be stated on the assignment, syllabus, or gradebook — don't assume it's 100 just because that's the most familiar total.
- Divide the raw score by the maximum, then multiply by 100 to get a percentage.
- Apply your school's percentage-to-letter-grade chart to that percentage (see the standard chart below, but check your own institution's official cutoffs).
- If converting for GPA purposes, take the resulting letter grade and look up its grade point value using your school's GPA scale.
Worked conversions from common raw scales
| Raw Score | Out of | Percentage | Common Letter Grade |
|---|---|---|---|
| 17 | 20 | 85% | B / B+ |
| 42 | 50 | 84% | B |
| 9 | 10 | 90% | A- |
| 34 | 40 | 85% | B / B+ |
| 156 | 200 | 78% | C+ |
| 7.5 | 10 | 75% | C |
Standard percentage-to-letter chart (for reference)
Once you have a percentage, apply a chart like the one below — a widely used convention, though your specific school's cutoffs may differ:
| Percentage | Letter Grade |
|---|---|
| 93–100 | A |
| 90–92 | A- |
| 87–89 | B+ |
| 83–86 | B |
| 80–82 | B- |
| 77–79 | C+ |
| 73–76 | C |
| 70–72 | C- |
| 67–69 | D+ |
| 63–66 | D |
| 60–62 | D- |
| Below 60 | F |
Our full 100-point to GPA scale guide covers this chart and its GPA-point conversion in more depth.
Why the "grading culture" behind the number matters
This is where converting a raw numeric grade differs meaningfully from converting a straightforward percentage: the scale's total (20, 10, or otherwise) is often tied to a specific grading tradition with its own norms about what counts as a strong score. A 13 out of 20 reduces mathematically to 65%, which looks like a low grade on a US percentage scale where the 90s are reserved for top performers. But under many European grading conventions — French and several other systems commonly use a 0–20 scale — a 13 or 14 is often a genuinely solid, above-average result, because scores above 16 are deliberately rare even for excellent students.
This means converting a raw numeric grade in two different ways can produce two different answers:
| Method | 13/20 Converts To |
|---|---|
| Literal percentage reduction (13÷20=65%) applied to a US chart | D+ or C- |
| Grading-culture-aware conversion table (accounting for a compressed 0–20 scale) | B or B- |
If the numeric grade comes from a US assignment simply scored out of a non-100 total (like a 20-point quiz graded on ordinary US grading norms), the literal percentage reduction is usually the right approach. If it comes from a different country's grading system entirely, a culture-aware conversion table — like the ones used by credential evaluators — is more accurate. See our guide on how credential evaluation services convert foreign transcripts for how that distinction is handled formally.
Common edge cases
- Extra credit pushing a score above the maximum. A raw score of 22 out of 20 (110%) should generally still be capped according to your school's policy on how percentages above 100% are handled for letter-grade purposes — some cap the letter at the top grade, others allow the extra credit to offset a different assignment's low score in a weighted average.
- Different maximums for different assignments in the same course. If quizzes are scored out of 10 and exams out of 100, don't average the raw scores directly — convert each to a percentage first, then combine using whatever weighting the syllabus specifies (for example, quizzes worth 20% of the final grade, exams worth 50%).
- Rounding at the percentage or raw-score stage. Whether your instructor rounds 84.5% up to 85% before applying the letter chart, or applies the chart to the unrounded decimal, can shift a borderline grade — check the syllabus's stated policy if your score is close to a cutoff.
- Negative or bonus-point scoring systems. Some courses use scoring systems where points are subtracted from a maximum rather than added up, or where the "maximum" itself is a moving target across the term — these need to be handled according to that specific course's documented grading method rather than a generic formula.
Try it yourself
Once you've converted your raw numeric scores to percentages, our Percentage to Letter Grade Calculator applies the standard cutoffs automatically, and our GPA Calculator can take the resulting letter grades and credit hours to compute your overall GPA — both run entirely in your browser, with no account or upload required.
