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How Many Questions Can I Miss Calculator
Before a test it helps to know your margin. Enter the number of questions and the lowest score you want. The calculator tells you how many you can miss, what you would score if you missed exactly that many, and what happens if you miss one more. A quick table also covers the usual 90/80/70/60 cut-offs.
The math: allowed misses = number of questions × (1 − target ÷ 100), rounded down, because missing part of a question is not possible. On a 40-question test aiming for 80%, 40 × 0.20 = 8, so you can miss 8 (32/40 = 80%), but a ninth miss drops you to 77.5%. When the division is not exact you always round down. On a 25-question test aiming for 90%, 25 × 0.10 = 2.5, so you can miss only 2.
This assumes every question is worth the same. If sections carry different points, work in points instead: enter total points as the number of questions and use 1 point each. For partial credit, or a grade across a whole course, use the final exam and grade-needed calculators linked below.
Result and step-by-step working
Miss 8 of 40 and you score 80%. Miss 9 and you drop to 77.5%. Each question is worth 2.5% (1 point).
| Target | Can miss | Score if you miss that many |
|---|---|---|
| 90% | 4 | 90% |
| 80% | 8 | 80% |
| 70% | 12 | 70% |
| 60% | 16 | 60% |
- Allowed wrong answers40 × (1 − 80/100) = 8.
- Round downYou cannot miss part of a question, so round down: 8.
- Check(40 − 8) ÷ 40 × 100 = 80%, which is at least 80%.
Frequently asked questions
- How many can I miss on a 50-question test and get a 90?
- Five. 50 × (1 − 0.90) = 5, and 45/50 = 90%.
- How many can I miss on a 20-question test to pass with 70%?
- Six. 20 × 0.30 = 6, and 14/20 = 70%. A seventh miss gives 65%.
- How much is each question worth?
- 100 ÷ number of questions. On a 40-question test each question is worth 2.5%. On a 30-question test, about 3.33%.
- What if the teacher rounds scores?
- If 89.5% is rounded to 90%, you may get one more miss than this shows. The calculator does not assume rounding.
Last reviewed: October 9, 2026. Calculations run in your browser; nothing you enter is sent anywhere.