Before a test, it helps to know your margin: how many questions you can get wrong and still hit the score you need. Enter the number of questions and your target score, and this calculator gives the misses you can afford and the scores around your cutoff.
How to Use It
- Enter the Number of Questions on the test. If questions are worth different points, enter the total points instead.
- Enter the Score You Need as a percentage: 70 to pass, 90 for an A−.
- Press Calculate. You’ll see how many you can miss, how many you need right, and a small table of your score for each number missed near the cutoff.
How It Works
Your score is the share of questions you get right:
So the fewest correct answers that reach your target is the target share of the questions, rounded up, because you can’t get part of a question right:
Every other question is one you can miss.
Worked Example
A test has 50 questions and you need 80%. You need correct, so you can miss 10, and missing exactly 10 gives exactly 80%.
On a 23-question quiz where you need 70%, , which rounds up to 17 correct. You can miss 6, which scores 73.9%. Missing 7 would drop you to 69.6%.
Tips and Common Mistakes
- Round up, never down. Needing 16.1 correct means 17. Rounding down to 16 leaves you just short.
- Points aren’t always questions. If some questions are worth more, use total points: the result is then the points you can lose.
- Partial credit and curves only help. The calculator treats each question as right or wrong, so they can only improve your real score.
- Know your teacher’s rounding. If 89.5% rounds to 90%, you may have one more miss to spare.
- Aim for a buffer. Plan to miss fewer than the maximum; a surprise question can use up your margin.