Percent score from questions missed, with a grading chart
Updated October 2026
Each wrong answer on a 25-question test costs 4 points. The chart covers the first 12 misses; the calculator handles any length.
| Wrong | Right | Score | Letter |
|---|---|---|---|
| 0 | 25 | 100% | A+ |
| 1 | 24 | 96% | A |
| 2 | 23 | 92% | A- |
| 3 | 22 | 88% | B+ |
| 4 | 21 | 84% | B |
| 5 | 20 | 80% | B- |
| 6 | 19 | 76% | C |
| 7 | 18 | 72% | C- |
| 8 | 17 | 68% | D+ |
| 9 | 16 | 64% | D |
| 10 | 15 | 60% | D- |
| 11 | 14 | 56% | F |
| 12 | 13 | 52% | F |
The most you can miss and still reach a target percentage is the number of questions × (1 − target), rounded down. On a 40-question test, a 90% allows 4 misses (40 × 0.10 = 4); on a 30-question test it allows 3; on a 15-question test, only 1 (15 × 0.10 = 1.5, rounded down). Short quizzes are unforgiving: each question on a 10-question quiz is worth a full letter grade.
When questions are worth different amounts, enter total points instead of questions and points lost instead of the number wrong. A 50-point test where you lost 7 points scores 43 ÷ 50 = 86%. Partial credit works the same way: enter the points taken off, decimals allowed.
The curve field adds the same number of points to every score, the simplest kind of curve. Other curves (scaling the top score to 100%, or setting the class average to a target) depend on the whole class's results, so ask how your teacher curves before relying on it. Letter cut-offs here follow the common 10-point scale with plus/minus (93/90/87...); your school may use different cut-offs.