Test Grade Calculator
Turn the number you got right — or wrong — into a percentage and a letter grade, on whichever scale your school uses.
Score
—
Letter grade
—
Correct
—
Every score on this test
Useful for seeing how much one more mistake would cost.
| Wrong | Correct | Score | Grade |
|---|---|---|---|
Sign in or create a free account to save this calculation. Everything else works without one.
The percentage is fixed arithmetic; the letter grade is not. Schools set their cut-offs differently, so change the scale above if yours does not match.
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How to use this calculator
- Enter how many questions were on the test.
- Enter how many you got wrong, or switch to counting the ones you got right.
- Set your grading scale so the letter grade matches your school's.
How the calculation works
Every question counts equally. The number you got right, divided by the total, gives the proportion — multiply by 100 for a percentage.
Counting wrong answers is the same sum with one step first: correct = total − wrong.
A worked example
A 20-question test with 3 wrong:
- Correct: 20 − 3 = 17
- Proportion: 17 ÷ 20 = 0.85
- Percentage: 0.85 × 100 = 85%
On a standard scale with plus and minus grades, 85% is a B. On a scale without them it is also a B — but at 90% the two diverge: an A- on one, a plain A on the other.
Common test lengths
How much one wrong answer costs depends entirely on how long the test is:
| Questions | Each question | Score with 1 wrong | Score with 5 wrong |
|---|---|---|---|
| 10 | 10% | 90% | 50% |
| 20 | 5% | 95% | 75% |
| 25 | 4% | 96% | 80% |
| 40 | 2.5% | 97.5% | 87.5% |
| 50 | 2% | 98% | 90% |
Important notes and limitations
This assumes every question is worth the same
If your test had a long-answer question worth ten points and multiple-choice worth one each, question counts will give the wrong answer. Use the Grade Calculator and work in points instead.
- Part marks are not modelled — the calculator works in whole questions.
- Curves and dropped questions are applied by your instructor afterwards.
- Extra credit questions can push a score above 100%; count them in the correct answers but not in the total.
Frequently asked questions
How do I work out a test grade?
Divide the number you got right by the total number of questions, then multiply by 100. On a 20-question test, 17 right is 17 ÷ 20 = 0.85, so 85%.
What letter grade is my score?
That depends on your school's cut-offs. An 85% is a B on most standard scales, but some schools set a B at 84% and some at 86%. Switch the grading scale above to match yours.
My test had questions worth different amounts. What then?
Use the Grade Calculator, which works in points rather than question counts. This calculator assumes every question is worth the same.
How do I work out my grade for the whole course?
A single test is only part of it. If your course uses category weights, the Weighted Grade Calculator will combine them; if it is points-based, use the Grade Calculator.
What score do I need on the next test?
If the next assessment is a final, the Final Grade Calculator answers that directly — it works out the score you need to reach the course grade you want.