Grading Scale
The percentage each letter grade covers, on the two tables US schools publish most. Cutoffs are set by each school and district, so these are the site's defaults and every calculator takes your own instead.
10-point grading scale
Ten percentage points per letter, the table most US high schools use and the one the calculators start on. The cited page rounds a decimal score to the nearest whole percent before reading off the letter. The tables here take the percentage as it stands, so a score just under a cutoff keeps the lower letter.
| Letter | Percentage |
|---|---|
| A | 90% and above |
| B | 80% to 89% |
| C | 70% to 79% |
| D | 60% to 69% |
| F | 0% to 59% |
Source: Academic grading in the United States, read 2026-09-20.
Plus and minus grading scale
Three percentage points per step, which splits each letter into a plus, a plain letter and a minus. Many colleges grade this way and some high schools do.
| Letter | Percentage |
|---|---|
| A+ | 97% and above |
| A | 93% to 96% |
| A- | 90% to 92% |
| B+ | 87% to 89% |
| B | 83% to 86% |
| B- | 80% to 82% |
| C+ | 77% to 79% |
| C | 73% to 76% |
| C- | 70% to 72% |
| D+ | 67% to 69% |
| D | 63% to 66% |
| D- | 60% to 62% |
| F | 0% to 59% |
Source: Academic grading in the United States, read 2026-09-20.
The cited page introduces this table as one some colleges use, not a national standard.
Where the two grading scales disagree
The same score earns a different letter on each table: 89% is a B on the 10-point scale and a B+ where pluses and minuses are awarded. The scale picker on the grade calculator switches between the two, and the grade points each letter is then worth are on the GPA scale page.
| Score | Standard 10-point scale | Plus/minus scale |
|---|---|---|
| 100% | A | A+ |
| 90% | A | A- |
| 89% | B | B+ |
| 80% | B | B- |
| 79% | C | C+ |
| 70% | C | C- |
| 69% | D | D+ |
| 60% | D | D- |
| 59% | F | F |
Source: Academic grading in the United States, read 2026-09-20.