Each question on a 30-question test is worth 3.33%. On the 10-point scale the lowest A is 27/30 (90%), the lowest B is 24/30, the lowest C is 21/30 and the lowest D is 18/30. 17 right or fewer is an F.
30-question grading chart
| Right | Wrong | Percent | Grade | Plus/minus |
|---|---|---|---|---|
| 30 | 0 | 100% | A | A |
| 29 | 1 | 96.7% | A | A |
| 28 | 2 | 93.3% | A | A |
| 27 | 3 | 90% | A | A− |
| 26 | 4 | 86.7% | B | B+ |
| 25 | 5 | 83.3% | B | B |
| 24 | 6 | 80% | B | B− |
| 23 | 7 | 76.7% | C | C+ |
| 22 | 8 | 73.3% | C | C |
| 21 | 9 | 70% | C | C− |
| 20 | 10 | 66.7% | D | D+ |
| 19 | 11 | 63.3% | D | D |
| 18 | 12 | 60% | D | D− |
| 17 | 13 | 56.7% | F | F |
| 16 | 14 | 53.3% | F | F |
| 15 | 15 | 50% | F | F |
| 14 | 16 | 46.7% | F | F |
| 13 | 17 | 43.3% | F | F |
| 12 | 18 | 40% | F | F |
| 11 | 19 | 36.7% | F | F |
| 10 | 20 | 33.3% | F | F |
| 9 | 21 | 30% | F | F |
| 8 | 22 | 26.7% | F | F |
| 7 | 23 | 23.3% | F | F |
| 6 | 24 | 20% | F | F |
| 5 | 25 | 16.7% | F | F |
| 4 | 26 | 13.3% | F | F |
| 3 | 27 | 10% | F | F |
| 2 | 28 | 6.7% | F | F |
| 1 | 29 | 3.3% | F | F |
| 0 | 30 | 0% | F | F |
Grades use the 10-point scale (A 90–100, B 80–89, C 70–79, D 60–69, F below 60) on the percentage rounded to a whole number, so 93.3% counts as 93%. The plus/minus column splits each band in thirds, such as B− 80–82, B 83–86 and B+ 87–89: a common split, but schools differ. Your school’s policy has the last word.
Common scores out of 30
- 23/30 is 76.7%: a C (C+ with plus and minus). 1 more right would make it a B.
- 24/30 is 80%: a B (B− with plus and minus). 3 more right would make it an A.
- 20/30 is 66.7%: a D (D+ with plus and minus). 1 more right would make it a C.
- 26/30 is 86.7%: a B (B+ with plus and minus). 1 more right would make it an A.
- 25/30 is 83.3%: a B. 2 more right would make it an A.
- 22/30 is 73.3%: a C. 2 more right would make it a B.
- 27/30 is 90%: an A (A− with plus and minus).
The same grade on other test lengths
The score that gives each percentage on the test lengths teachers use most. Where it’s a half score, such as 13.5/15, you need the next whole score (14/15) if you don’t give half points.
| Grade | 15 questions | 20 questions | 25 questions | 30 questions | 50 questions |
|---|---|---|---|---|---|
| 90% (A) | 13.5/15 | 18/20 | 22.5/25 | 27/30 | 45/50 |
| 80% (B) | 12/15 | 16/20 | 20/25 | 24/30 | 40/50 |
| 70% (C) | 10.5/15 | 14/20 | 17.5/25 | 21/30 | 35/50 |
| 60% (D) | 9/15 | 12/20 | 15/25 | 18/30 | 30/50 |
For any other length, use the teacher grade calculator.
Questions
Is 18 out of 30 passing?
18/30 is 60%, a D on the 10-point scale. A D is the lowest passing grade there: Florida’s law calls it “lowest acceptable progress” and anything under 60% a failure. Your course may set a higher pass mark, so check the syllabus.
What is 80% of 30 questions?
24 right. 24/30 is the lowest B on the 10-point scale.
How many can you miss and still get an A?
3 questions. 27/30 is 90%; one more wrong answer gives 86.7%, a B.
Sources
- Florida Statutes §1003.437, Middle and high school grading system: A 90–100%, B 80–89%, C 70–79%, D 60–69% (“lowest acceptable progress”), F 0–59%.
- College Board BigFuture, How to Calculate Your GPA on a 4.0 Scale: a commonly used chart with A 90–100, B 80–89 and C 70–79; it notes that schools use different cutoffs.