What is my test grade?
Enter the number of questions and how many were wrong. Or fill in any two of questions, wrong, right, and grade.
- Grade
- 85%
6 wrong out of 40 is 85% (B).
B
- F
- D-
- D
- D+
- C-
- C
- C+
- B-
- B
- B+
- A-
- A
- Right
- 34
- Letter grade
- B
Grade: 85%. 6 wrong out of 40 is 85% (B).
How to calculate
Computes a test grade in percent and its letter from the number of questions and the number wrong, or finds the number wrong allowed for a grade.
Example with the default inputs (Questions 40, Wrong 6): 6 wrong out of 40 is 85% (B).
Formula: right = questions − wrong; grade = 100 × right ÷ questions
- Every question is worth the same, or the numbers are points: questions as points possible, wrong as points lost.
- Fill in any two of questions, wrong, right, and grade; the calculator finds the other two.
- Letter grades follow the Tompkins Cortland Community College (SUNY) scale: A 93 and up, A- 90 to below 93, B+ 87, B 83, B- 80, C+ 77, C 73, C- 70, D+ 67, D 63, D- 60, F below 60.
Worked examples
Each example is checked against the calculator on every build.
- Questions 40, Wrong 6 gives Right 34, Grade 85%, Letter grade B.Source: hand calculation in content.mdx: 100 × (40 − 6) ÷ 40 = 85%
- Questions 25, Wrong 2 gives Right 23, Grade 92%, Letter grade A-.Source: hand calculation in content.mdx: 100 × 23 ÷ 25 = 92%
- Questions 30, Grade 80% gives Right 24, Wrong 6, Letter grade B-.Source: hand calculation in content.mdx: 80 × 30 ÷ 100 = 24 right, 6 wrong
- Wrong 3, Grade 85% gives Questions 20, Right 17.Source: hand calculation in content.mdx: questions = 100 × 3 ÷ (100 − 85) = 20
- Questions 12, Wrong 5 gives Grade 58.333333%, Letter grade F.Source: hand calculation in content.mdx: 100 × 7 ÷ 12 = 58.33%
How it works
Two equations link the four numbers:
- right = questions − wrong
- grade = 100 × right ÷ questions
Together they give a third, used when you know the wrong answers and the grade:
- wrong = questions × (100 − grade) ÷ 100, so questions = 100 × wrong ÷ (100 − grade)
Fill in any two and the calculator finds the other two. For example, from questions and a grade: right = grade × questions ÷ 100, then wrong = questions − right.
The grade gets a letter on the Tompkins Cortland Community College scale. A grade belongs to a letter when it is at or above that letter's lower limit and below the next one's.
- A: 93 and up
- A-: 90 to below 93
- B+: 87 to below 90
- B: 83 to below 87
- B-: 80 to below 83
- C+: 77 to below 80
- C: 73 to below 77
- C-: 70 to below 73
- D+: 67 to below 70
- D: 63 to below 67
- D-: 60 to below 63
- F: below 60
Assumptions
- Every question is worth the same. For tests with different points per question, use points throughout.
- Questions are at least 1; the grade is from 0% to 100%.
- More wrong (or right) answers than questions gives no answer, and so do values that no test fits (for example 0 wrong at a grade below 100%).
- Solved counts are not rounded, so a count that is not a whole number means no whole number of questions fits exactly.
Worked examples by hand
6 wrong out of 40. Right: 40 − 6 = 34. Grade: 100 × 34 ÷ 40 = 85%, a B.
2 wrong out of 25. Right: 23. Grade: 100 × 23 ÷ 25 = 92%, an A-.
80% on a 30-question test. Right: 80 × 30 ÷ 100 = 24. Wrong: 30 − 24 = 6. 80% is a B-.
3 wrong at 85%. Questions: 100 × 3 ÷ (100 − 85) = 300 ÷ 15 = 20. Right: 20 − 3 = 17.
5 wrong out of 12. Right: 7. Grade: 100 × 7 ÷ 12 = 58.33%, an F.
Other questions people ask
How do I calculate a test grade?
Subtract the wrong answers from the number of questions, divide by the number of questions, and multiply by 100. With 6 wrong out of 40: (40 − 6) ÷ 40 × 100 = 34 ÷ 40 × 100 = 85%.
How many questions can I miss and still get a B?
A B starts at 83% on this page's scale. Enter the number of questions and 83 as the grade: the calculator shows the right answers needed (83% of the questions) and the wrong answers that leaves. On a 30-question test, 83% is 24.9 right, so you need 25 right and can miss 5 (25 ÷ 30 = 83.33%).
What if the questions are worth different points?
Use points. Enter the points possible as questions and the points lost as wrong. A 50-point test with 7 points lost is (50 − 7) ÷ 50 = 86%.
Can I find the number of questions from the grade?
Yes. With 3 wrong and a grade of 85%, questions = 100 × 3 ÷ (100 − 85) = 20. If the answer is not a whole number, no test length gives exactly that grade with that many wrong.
Which letter grade scale is used?
The Tompkins Cortland Community College (SUNY) scale: A 93 and up, A- 90 to 92, B+ 87 to 89, B 83 to 86, B- 80 to 82, C+ 77 to 79, C 73 to 76, C- 70 to 72, D+ 67 to 69, D 63 to 66, D- 60 to 62, F 59 and below. Teachers often set their own cutoffs.
Is a test grade the same as a test score?
They use the same percent. This page starts from the wrong answers, which is how a teacher marks a test. To start from the points you earned, use the test score calculator.