40 questions, 7 wrong
33 right, 82.5%, a B−.
Test grade calculator
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Every question is worth the same. The letter grade uses the common US scale: A from 90%, B from 80%, C from 70%, D from 60%, F below 60%, with plus and minus bands. Your teacher or school may use a different scale or a curve.
I know the number
Score
82.5%
33 out of 40 right is 82.50%, a B− on the standard scale. Each question is worth 2.50 percentage points.
- Letter grade
- B−
- Right
- 33
- Wrong
- 7
- Points per question
- 2.50
Grades for a 40-question test
| Wrong | Score | Percent | Grade |
|---|---|---|---|
| 0 | 40 / 40 | 100.0% | A+ |
| 1 | 39 / 40 | 97.5% | A+ |
| 2 | 38 / 40 | 95.0% | A |
| 3 | 37 / 40 | 92.5% | A− |
| 4 | 36 / 40 | 90.0% | A− |
| 5 | 35 / 40 | 87.5% | B+ |
| 6 | 34 / 40 | 85.0% | B |
| 7 | 33 / 40 | 82.5% | B− |
| 8 | 32 / 40 | 80.0% | B− |
| 9 | 31 / 40 | 77.5% | C+ |
| 10 | 30 / 40 | 75.0% | C |
| 11 | 29 / 40 | 72.5% | C− |
| 12 | 28 / 40 | 70.0% | C− |
| 13 | 27 / 40 | 67.5% | D+ |
| 14 | 26 / 40 | 65.0% | D |
| 15 | 25 / 40 | 62.5% | D− |
| 16 | 24 / 40 | 60.0% | D− |
| 17 | 23 / 40 | 57.5% | F |
| 18 | 22 / 40 | 55.0% | F |
| 19 | 21 / 40 | 52.5% | F |
| 20 | 20 / 40 | 50.0% | F |
| 21 | 19 / 40 | 47.5% | F |
From wrong answers to a letter grade
Most quick grade calculators start from the number of wrong answers, because that is what you count when you mark a test. The score is the right answers over the total, and the letter grade comes from the band that score falls in.
On a 40-question test with 7 wrong, you got 33 right. 33 ÷ 40 = 0.825, or 82.5%, which is a B− on the usual US scale. Each question is worth 2.5 percentage points, so one more right answer would have made it 85%, a B.
Teachers use the chart below the result as a grading key: one row for each number wrong, with the percentage and letter grade. It stops once scores drop below 50%, since anything lower is an F either way.
Grading scales vary. Some schools drop the plus and minus, some start an A at 93%, and some curve the results. If your syllabus lists a different scale, use the percentage and look it up there.
Sources
What this calculator does not account for
- Uses the common US plus/minus scale.
- Not for weighted sections or curved grades.
How this is calculated
Formula: Test score
score % =right answers ÷ total questions × 100What the symbols mean
- right answersTotal questions minus the ones you got wrong.
- total questionsEvery question counts the same.
Good to know
- Letter grade: A from 90%, B from 80%, C from 70%, D from 60%, F below 60%, with plus and minus in each band.
- To see what you need on a final exam, use the final grade calculator.
Read the full methodologyFound an error? Contact us
Worked examples
Each example is worked out by the same code as the calculator above.
40 questions, 4 wrong
36 right, 90%, an A−.
Embed this calculator
The frame shows the tool only.
<iframe src="/embed/test-grade-calculator" title="Test grade" width="100%" height="720" style="border:0;max-width:42rem" loading="lazy"></iframe>Questions
How do I calculate my test grade?
Divide the questions you got right by the total and multiply by 100. On a 40-question test with 7 wrong, 33 ÷ 40 = 82.5%.
What grade is 82.5%?
A B− on the common US scale, where 80% to 82.9% is B−, 83% to 86.9% is B and 87% to 89.9% is B+.
How many questions can I miss and still get an A?
On a 40-question test, you can miss 4 for exactly 90%. The table shows the cut-off for any test length.
Is 70% a passing grade?
70% is a C− on this scale. Many US schools pass anything from 60% (D−), though some courses need a C or better.
Does this work for tests with different point values?
Only if every question is worth the same. For weighted sections, use the weighted average calculator.