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Education & Math

Test Grade Calculator

Miss 3 questions out of 20 and you score 85%, a B. This test grade calculator turns total questions and questions missed into a percentage score and a letter grade. Teachers use it to grade a stack of quizzes fast, and students use it to see how many questions they can afford to miss.

Education & MathBy

Quick answer

Score = correct answers divided by total questions, times 100.

Score

85%

Letter grade

B

Correct answers

17 of 20

What this tells you

  • Score = correct answers divided by total questions, times 100.
  • Letter grades use the standard scale: A 90+, B 80-89, C 70-79, D 60-69, F below 60.
  • Every question is weighted equally.
  • Enter the questions missed, not the questions correct.

How to Use

  1. 1Enter the total number of questions on the test.
  2. 2Enter how many questions were answered wrong.
  3. 3Read the percentage score and letter grade below.

How It Works

Formula

score % = (total - wrong) / total x 100

Subtract the wrong answers from the total to get the correct count, divide by the total, then multiply by 100. For a 20 question test with 3 wrong, that is 17 divided by 20 times 100, which is 85%.

Calculation note: values are processed in the order shown above, using the current input units.

Worked Examples

20 questions, 3 wrong

Total Questions20
Wrong Answers3
Result85% (B)

17 of 20 correct is 85%, which lands in the B range on the standard scale.

50 questions, 8 wrong

Total Questions50
Wrong Answers8
Result84% (B)

42 of 50 correct is 84%.

Grades for a 20 Question Test

Score and letter grade by questions missed.

Wrong answersScoreLetter grade
0100%A
195%A
290%A
385%B
480%B
575%C
670%C
860%D
955%F

Letter grades assume the common 90/80/70/60 scale. Your school may use different cutoffs.

Common mistakes

  • Entering correct answers in the wrong field. This tool asks for questions missed.
  • Assuming every school uses the 90/80/70/60 scale. Some use plus and minus bands or a 93 cutoff for an A.
  • Using it for weighted tests. If some questions are worth more points, grade by points instead of question counts.

Frequently Asked Questions

Divide the number of correct answers by the total questions and multiply by 100. Getting 17 of 20 correct is 85%.
3 wrong out of 20 is 85%, which is a B on the standard scale.
You can miss up to 10 percent of the questions on the 90 percent scale. On a 20 question test that is 2 questions, and on a 50 question test it is 5.
75% is a C on the common 90/80/70/60 scale.
No. This calculator treats each question as fully right or fully wrong, so grade by total points when partial credit applies.
It estimates test grade calculator outputs using the visible inputs and formula assumptions on this page.

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