Calculate a Test or Quiz Grade
Count the wrong answers, or switch to entering the number correct.
Custom Grade Scale
Grading Chart: 25 Questions
Every possible number wrong for this test, using your selected scale and rounding. Your current score is highlighted.
| Wrong | Correct | Percentage | Letter grade |
|---|
How to Calculate a Test Grade
Subtract the number of wrong answers from the total number of questions to get the number correct. Divide by the total and multiply by 100.
Test grade (%) = (total questions − wrong) ÷ total questions × 100Example: a 25-question test with 4 wrong answers has 21 correct. 21 ÷ 25 = 0.84, so the test grade is 84%, a B on the common US +/- scale.
How Much Is Each Question Worth?
When every question carries the same marks, each one is worth 100 ÷ total questions percent. On a 20-question test each question is worth 5%, on a 25-question test 4%, and on a 40-question test 2.5%. So every wrong answer lowers the grade by that amount.
Quiz Grade Calculator
Quizzes work exactly the same way. For a 10-question quiz with 2 wrong, enter 10 as the total and 2 as wrong: 8 ÷ 10 = 80%. Short quizzes move in big steps (10% per question on a 10-question quiz), so a single mistake can change the letter grade.
Grading Chart for Teachers
Enter the number of questions once and the chart lists the percentage and letter grade for every possible number wrong. Click Print chart to print only the table and keep it beside you while marking. This works like the paper "easy grader" slide charts many teachers use.
Quick Answers for Common Test Lengths
Percentages below are exact (no rounding).
| Test | 1 wrong | 2 wrong | 3 wrong | 5 wrong |
|---|---|---|---|---|
| 10 questions | 90% | 80% | 70% | 50% |
| 15 questions | 93.33% | 86.67% | 80% | 66.67% |
| 20 questions | 95% | 90% | 85% | 75% |
| 25 questions | 96% | 92% | 88% | 80% |
| 30 questions | 96.67% | 93.33% | 90% | 83.33% |
| 40 questions | 97.5% | 95% | 92.5% | 87.5% |
| 50 questions | 98% | 96% | 94% | 90% |
When to Use a Different Calculator
If questions are worth different points (for example a test with multiple-choice and essay sections), add up the points instead and use the Grade Calculator in points mode. To combine test scores with homework and quizzes that carry different weights, use the Weighted Grade Calculator. To find what you need on a final exam, use the Final Grade Calculator.
Frequently Asked Questions
How do I calculate my test grade if I got some wrong?
Subtract the wrong answers from the total questions, divide by the total and multiply by 100. For example, 3 wrong on a 20-question test is 17 ÷ 20 × 100 = 85%.
What is 4 wrong out of 25?
21 out of 25 correct, which is 84%. That is a B on the common US +/- scale.
How many questions can I miss and still get an A?
With an A starting at 90%, you can miss 10% of the questions: 1 on a 10-question test, 2 on a 20-question test, 2 on a 25-question test (2.5 rounded down) and 5 on a 50-question test. The calculator shows this for your test under "Wrong answers allowed for 90%".
Can I give half marks?
Yes. Enter values such as 2.5 wrong. The calculator treats each half mark as half a question.
Does this work for quizzes and exams?
Yes, as long as every question is worth the same amount. For tests with different point values, use the points mode on the Grade Calculator.
Is the test grade calculator free?
Yes. It runs in your browser, needs no sign-up and does not upload anything.