How to work out 18 out of 30
Divide the score by the total and multiply by 100: 18 ÷ 30 = 0.6, and 0.6 × 100 = 60%.
That means 12 answers were wrong, and each question was worth 3.33% of the total. One more correct answer (19/30) would be 63.33%.
Grading chart for 30 questions
| Wrong | Score | Percent | Grade |
|---|---|---|---|
| 0 | 30/30 | 100% | A+ |
| 1 | 29/30 | 96.7% | A |
| 2 | 28/30 | 93.3% | A |
| 3 | 27/30 | 90% | A− |
| 4 | 26/30 | 86.7% | B |
| 5 | 25/30 | 83.3% | B |
| 6 | 24/30 | 80% | B− |
| 7 | 23/30 | 76.7% | C |
| 8 | 22/30 | 73.3% | C |
| 9 | 21/30 | 70% | C− |
| 10 | 20/30 | 66.7% | D |
| 11 | 19/30 | 63.3% | D |
| 12 | 18/30 | 60% | D− |
| 13 | 17/30 | 56.7% | F |
| 14 | 16/30 | 53.3% | F |
| 15 | 15/30 | 50% | F |
| 16 | 14/30 | 46.7% | F |
| 17 | 13/30 | 43.3% | F |
| 18 | 12/30 | 40% | F |
| 19 | 11/30 | 36.7% | F |
| 20 | 10/30 | 33.3% | F |
| 21 | 9/30 | 30% | F |
| 22 | 8/30 | 26.7% | F |
| 23 | 7/30 | 23.3% | F |
| 24 | 6/30 | 20% | F |
| 25 | 5/30 | 16.7% | F |
| 26 | 4/30 | 13.3% | F |
| 27 | 3/30 | 10% | F |
| 28 | 2/30 | 6.7% | F |
| 29 | 1/30 | 3.3% | F |
| 30 | 0/30 | 0% | F |
Letter grades use the common US scale (A ≥ 93%, B ≥ 83%, C ≥ 73%, D ≥ 63%, with ± bands). Your school may use different cut-offs.