How to work it out
15 ÷ 20 = 0.75
0.75 × 100 = 75%
Divide the score by the total, then multiply by 100. 15 out of 20 means you got 15 of 20 right and missed 5, so each question is worth 5%.
16 out of 20 (80%) would move you up to a B−.
Every score out of 20
| Score | Percent | Letter grade |
|---|---|---|
| 20 out of 20 | 100% | A |
| 19 out of 20 | 95% | A |
| 18 out of 20 | 90% | A− |
| 17 out of 20 | 85% | B |
| 16 out of 20 | 80% | B− |
| 15 out of 20 | 75% | C |
| 14 out of 20 | 70% | C− |
| 13 out of 20 | 65% | D |
| 12 out of 20 | 60% | D− |
| 11 out of 20 | 55% | F |
| 10 out of 20 | 50% | F |
| 9 out of 20 | 45% | F |
| 8 out of 20 | 40% | F |
| 7 out of 20 | 35% | F |
| 6 out of 20 | 30% | F |
| 5 out of 20 | 25% | F |
| 4 out of 20 | 20% | F |
| 3 out of 20 | 15% | F |
| 2 out of 20 | 10% | F |
| 1 out of 20 | 5% | F |
| 0 out of 20 | 0% | F |
Letter grades use the common US scale (93 and up is an A, 90–92 an A−, and so on, below 60 an F). Your school or teacher may use a different one.