How to calculate a test grade
To calculate a test grade, subtract the number wrong from the number of questions, divide by the number of questions and multiply by 100. If questions carry different point values, do the same with points: points earned ÷ points possible.
test grade = (total − wrong) ÷ total × 100Each question is worth 100 ÷ total percent.
On a 30-question test, each question is worth 100 ÷ 30 = 3.33%. Missing 4 questions loses 13.33 points, for a score of 86.67%. The calculator also prints a chart of every possible number wrong, which is the quickest way to see how many you can miss and still get an A or B.
Test grade chart for common test lengths
Each cell is the percent score for that number of wrong answers. Find your test length across the top and your number wrong down the side.
| Wrong | 10 Qs | 15 Qs | 20 Qs | 25 Qs | 30 Qs | 40 Qs | 50 Qs |
|---|---|---|---|---|---|---|---|
| 1 | 90 | 93.3 | 95 | 96 | 96.7 | 97.5 | 98 |
| 2 | 80 | 86.7 | 90 | 92 | 93.3 | 95 | 96 |
| 3 | 70 | 80 | 85 | 88 | 90 | 92.5 | 94 |
| 4 | 60 | 73.3 | 80 | 84 | 86.7 | 90 | 92 |
| 5 | 50 | 66.7 | 75 | 80 | 83.3 | 87.5 | 90 |
| 6 | 40 | 60 | 70 | 76 | 80 | 85 | 88 |
| 8 | 20 | 46.7 | 60 | 68 | 73.3 | 80 | 84 |
| 10 | 0 | 33.3 | 50 | 60 | 66.7 | 75 | 80 |
To stay at 90% or above (an A− or better on a plus/minus scale[1]), you can miss 1 question in 10, 2 in 20, 2 in 25 (92%), 3 in 30, 4 in 40 and 5 in 50.
Exam grade calculator for mixed point values
Many exams mix a multiple-choice section with short answers or essays worth more points. Count points lost, not questions missed, and enter the exam’s total points in the first box.
Worked example
A 60-point exam has 40 one-point multiple-choice questions and two essays worth 10 points each. You miss 6 multiple-choice questions and lose 4 points across the essays.
Points lost: 6 + 4 = 10. Score: (60 − 10) ÷ 60 = 83.3%. Counting questions instead (8 “wrong” items out of 42) would give 81%, which is not how the test is graded.
How curved test grades work
A curve is any rule a teacher uses to raise scores after the test. Three simple versions are shown below; the syllabus or the teacher decides which, if any, applies.
| Curve | Rule | Curved score |
|---|---|---|
| Flat points | Add the same points to everyone (here +8, so the top score becomes 100%) | 72% |
| Scale to the top score | Your score ÷ top score × 100 | 69.6% |
| Square root | 10 × √(raw score) | 80% |
The square-root curve helps low scores most and leaves 100% unchanged; scaling to the top score helps everyone in proportion. Enter the curved score in the grade calculator or the weighted grade calculator to see its effect on the class.
Easy grade calculator for teachers
The chart in the result card is an “easy grader”: set the number of questions once and read every score down the column. It shows up to 25 wrong answers, with the row for the current entry highlighted. For letter grades, the chart uses the plus/minus 10-point scale; to grade on whole letters (A 90–100, B 80–89, and so on)[2] or another cut-off, use the letter grade calculator.
Before a finalWork out the score you need with the what do I need on my final page, then come back here and turn it into a number of questions you can miss.
Frequently asked questions
How do I calculate my test grade?
Divide the number of questions you got right by the total number of questions and multiply by 100. 17 right out of 20 is 85%.
What is 3 wrong out of 20?
85%. Each question on a 20-question test is worth 5 points.
How many can I miss on a 25-question test and get an A?
Two. Missing 2 gives 92% and missing 3 gives 88%.
How do I grade a test with different point values?
Use points instead of questions: (total points − points lost) ÷ total points × 100.