How to use the exam score calculator
- Enter the points earned and points possible for your exam.
- Select a curve type if your instructor applies one (add points, add percent, or scale to top score).
- For add points or add percent, enter the amount in Points or percent to add. For scale to top score, enter the class top score in points and the percentage it should become.
- Read your raw percent, curved percent, letter grade, and points needed for the next grade.
How the exam percentage is calculated
The core formula behind every exam score calculator is straightforward: divide the points earned by the points possible, then multiply by 100. For example, if you scored 42 out of 50, the math is 42 / 50 * 100 = 84%. That test score percentage maps to a letter grade using the plus/minus scale shown below, where 93 to 96.99 is an A, 90 to 92.99 is an A-, 87 to 89.99 is a B+, and so on.
When points possible is zero, the calculation is undefined. The tool treats this as an error rather than returning infinity or NaN, because a test worth zero points has no meaningful percentage.
How each curve method works
Instructors use different methods to adjust scores after an exam. Here is how each option in this exam percentage calculator operates:
- Add points: Adds a flat number of points to your earned score before calculating the percentage. If you earned 38 out of 50 and the curve adds 5 points, your adjusted score is 43 out of 50, giving 86%. The adjusted score never exceeds the points possible.
- Add percent: Calculates your raw percentage first, then adds the specified number of percentage points. A raw score of 60% with a 10-point curve becomes 70%. The result is capped at 100%.
- Scale to top score: Needs two inputs: the highest score in the class (in points) and the percentage that score should become, usually 100. The curved percentage is
raw percent / top percent x target percent. If the top raw score was 92 out of 100 and the instructor scales it to 100%, the multiplier is100 / 92 = 1.08696, so your 74% becomes74 x 1.08696 = 80.43%.
Standard letter grade scale
This tool uses a thirteen-level plus/minus grading scale (A+, A, A-, B+, B, B-, C+, C, C-, D+, D, D- and F). A starts at 93 and A+ at 97. Schools that use only whole letters (A from 90, B from 80) will give different letters for scores such as 91 or 85, so check your syllabus.
| Letter | Percentage range |
|---|---|
| A+ | 97 to 100 |
| A | 93 to 96.99 |
| A- | 90 to 92.99 |
| B+ | 87 to 89.99 |
| B | 83 to 86.99 |
| B- | 80 to 82.99 |
| C+ | 77 to 79.99 |
| C | 73 to 76.99 |
| C- | 70 to 72.99 |
| D+ | 67 to 69.99 |
| D | 63 to 66.99 |
| D- | 60 to 62.99 |
| F | Below 60 |
Points needed for the next letter grade
One of the most practical features of this exam score calculator is showing exactly how many more points you would have needed to reach the next letter grade. The tool looks up the minimum percentage for the next higher grade, works out how many raw points would produce that percentage after any curve, and subtracts what you actually earned.
For instance, if you scored 89 out of 100 with no curve (89%, a B+), the next grade is A- at 90%. You need 90 - 89 = 1 more point. If your exam was out of 50 and you scored 41 (82%, a B-), the next grade is B at 83%, which requires 0.83 x 50 = 41.5 points. Since partial points are rarely awarded, the tool rounds up to tell you that you need 1 more point (to reach 42).
The curve is taken into account. If you scored 40 out of 50 and the curve adds 3 points, you are at 43 out of 50, which is 86% and a B. A B+ needs 87%, or 43.5 curved points, which means 40.5 raw points, so you need 1 more raw point rather than 4.
Common mistakes when calculating test scores
Students frequently make errors when computing their test score percentage by hand. The most common mistake is dividing the points possible by the points earned instead of the other way around, which produces a number greater than 100% for any score below perfect. Another issue is forgetting to account for extra credit that increases the points possible denominator.
When applying curves, mixing up "add points" and "add percent" leads to very different results. Adding 5 points to a 50-point exam changes the percentage by 10 percentage points, while adding 5 percent only shifts the final number by 5 points on a 100-point scale. Always confirm which method your instructor uses before relying on an exam percentage calculator.
For standardized tests like the SAT or AP exams, scoring works differently. Use the dedicated SAT score calculator or AP exam score calculator for those specific formats.
Worked examples
| Example | Input | Result |
|---|---|---|
| Standard score | Points earned: 42; Points possible: 50; Curve type: none | Raw percent: 84%; Letter grade: B; Points needed for B+: 2 points |
| Add 5 points | Points earned: 38; Points possible: 50; Curve type: addPoints; Points or percent to add: 5 | Raw percent: 76%; Curved percent: 86%; Letter grade: B; Points needed for B+: 1 point |
| Add 10 percent | Points earned: 60; Points possible: 100; Curve type: addPercent; Points or percent to add: 10 | Raw percent: 60%; Curved percent: 70%; Letter grade: C-; Points needed for C: 3 points |
| Scale top score of 92 to 100% | Points earned: 74; Points possible: 100; Curve type: scaleToTop; Class top score (points): 92; Scale top score to (percent): 100 | Raw percent: 74%; Curved percent: 80.43%; Letter grade: B-; Points needed for B: 3 points |
FAQ
How do I calculate my test score percentage?
Divide the points you earned by the total points possible, then multiply by 100. For example, 37 out of 45 is 37 / 45 * 100 = 82.22%.
What does "scale to top score" mean?
It multiplies all scores by a factor so the highest score in the class reaches a target percentage. Enter the class top score in points and the percentage it should become. If the top score was 88 out of 100 and the target is 100%, every score is multiplied by 100 / 88.
Is adding points the same as adding percent?
No. Adding 5 points to a 50-point exam raises your score by 10 percentage points. Adding 5 percent simply adds 5 to your final percentage regardless of the total points.
Can my curved score exceed 100%?
This exam score calculator caps curved percentages at 100%. Some instructors allow scores above 100% as extra credit, but the standard practice is to cap at the maximum. You can still enter more points earned than points possible for extra credit work.
What happens if points possible is zero?
The tool returns an error because dividing by zero is mathematically undefined. An exam worth zero points cannot produce a valid percentage.
Does this work for AP or SAT exams?
AP and SAT exams use proprietary scoring formulas and composite scales. For those, use the dedicated AP exam score calculator or SAT score calculator instead.
How many points do I need for the next letter grade?
The calculator finds the minimum percentage for the next grade, converts it to the raw points you need after any curve, and shows the difference from your score rounded up to the nearest whole point.