There is no single US percent-to-letter scale. The conversion has two steps: pick the scale your syllabus uses, then find the band your percent falls in. This guide shows the common convention, four published school scales, and the examples where one percent earns three different letters.
Step 1 — Find your scale
Check your syllabus or course outline first. If it states cutoffs, use them. If it does not, ask the instructor. Do not assume the common scale matches — real schools publish 90, 92.50, 93, and 94 as the A cutoff.
Step 2 — Read the band
Each scale is a set of lower bounds: a percent earns the letter whose lower bound it reaches. Example on the common convention: 92% reaches the A− bound (90) but not the A bound (93), so it is A−.
The common convention
The most widely used form splits each 10-point band into plus/minus steps. It is a convention, not a rule.
| Letter | Common plus/minus | Straight 10-point | CU Denver (93) | UTC (90) | National (94) | UF Pharmacy (92.50) |
|---|---|---|---|---|---|---|
| A+ | 97–100 | — | — | — | — | — |
| A | 93–96 | 90–100 | 93–100 | 90–100 | 94–100 | 92.50–100 |
| A− | 90–92 | — | 90–92.9 | — | 90–93.99 | 89.50–92.49 |
| B+ | 87–89 | — | 87–89.9 | — | 87–89.99 | 86.50–89.49 |
| B | 83–86 | 80–89 | 83–86.9 | 80–89 | 83–86.99 | 82.50–86.49 |
| B− | 80–82 | — | 80–82.9 | — | 80–82.99 | 79.50–82.49 |
| C+ | 77–79 | — | 77–79.9 | — | 77–79.99 | 76.50–79.49 |
| C | 73–76 | 70–79 | 73–76.9 | 70–79 | 73–76.99 | 72.50–76.49 |
| C− | 70–72 | — | 70–72.9 | — | 70–72.99 | 69.50–72.49 |
| D+ | 67–69 | — | 67–69.9 | — | 67–69.99 | 66.50–69.49 |
| D | 63–66 | 60–69 | 63–66.9 | 60–69 | 63–66.99 | 62.50–66.49 |
| D− | 60–62 | — | 60–62.9 | — | 60–62.99 | 59.50–62.49 |
| F / E | Below 60 (F) | Below 60 (F) | Below 60 (F) | Below 60 (F) | 0–59.99 (F) | Below 59.50 (E) |
“—” means that letter does not exist on that scale. UF Pharmacy uses E, not F, as its failing letter. National’s graduate scale differs (F below 73, no D grades) and is not shown here.
Four published scales
- CU Denver Modern Languages (93-cutoff plus/minus). A starts at 93. Published by the department — a department scale, not a university-wide or national rule.
- UTC Doctor of Physical Therapy (90-cutoff straight). Straight letters, no plus/minus. UTC rounds half-up to a whole percent first: 89.4% → 89 (B); 89.5% → 90 (A).
- National University (94-cutoff plus/minus, undergraduate). A starts at 94. Its graduate scale differs (F below 73, no D grades).
- UF College of Pharmacy PharmD (92.50-cutoff). Program-level scale with .50 boundaries and X.495-up rounding. The failing letter is E, not F. Never label it “the UF scale” — UF’s catalog publishes no percent bands.
Same percent, different letters
| Percent | Common | Straight | CU Denver | UTC | National | UF Pharmacy |
|---|---|---|---|---|---|---|
| 92% | A− | A | A− | A | A− | A− |
| 59.6% | F | F | F | D* | F | D− |
*UTC rounds half-up to a whole percent first, so 59.6% becomes 60% → D. Without rounding it would be F.
Boundary and rounding rules
- Endpoint notation differs. CU Denver writes “90–92.9”; National writes “90–93.99”. Both mean A− starts at 90 and A starts at the next cutoff. This site uses lower bounds.
- Rounding is per-scale. The common convention assumes no rounding. UTC rounds half-up to a whole percent. UF Pharmacy rounds X.495+ up to X.50. If your syllabus states no rounding rule, do not assume one.
Common mistakes
- Treating the common scale as “the US scale.” There is no US-wide scale.
- Calling a program’s scale the university’s scale. UF Pharmacy’s 92.50 cutoff is a PharmD program scale.
- Assuming rounding. 89.5% is B+ on the common convention and A under UTC’s rounding.
- Reading a percent as a GPA. A percent maps to a letter; the letter maps to grade points only under a specific school’s table.
Calculate it: Percentage to Letter Grade Calculator. Grade points by university: ASU GPA Calculator, LSU GPA Calculator, Purdue GPA Calculator, UF GPA Calculator, UT Austin GPA Calculator.