Enter the points you earned (or the questions you missed) and the total. The calculator returns your percentage and letter grade right away.
How to calculate a test grade
A test percentage is the share of the available points you earned:
percentage = (points earned ÷ total points) × 100
If you only know how many answers were wrong, subtract them from the total first: points earned = total points − wrong answers. Then turn the percentage into a letter by finding the highest grade whose cutoff your percentage reaches.
The calculator keeps the exact fraction for the letter, and rounds the percentage to two decimals only for display. That matters when a score sits just under a cutoff: 17,999 of 20,000 displays as 90.00%, but the exact value is 89.995%, so the letter is B+ and not A-. The result box tells you when that happens.
How to use this calculator
- Choose whether you know the points earned or the number of questions wrong.
- Type the total number of points or questions on the test.
- Type the points earned, or the questions you got wrong. Decimals are fine, and a comma works as the decimal mark.
- Pick a scale: plus and minus grades, or letters only.
- Read the percentage and letter. Open the score table to see every possible score on the same test.
A score above the total is allowed, so extra credit works. The result shows a note when that happens.
The grading scale used here
There is no national grading scale in the United States. Each school or program sets its own, so check your syllabus. The default scale in this calculator is the percent-to-letter conversion published by the Johns Hopkins University School of Nursing, which matches the Queens College (CUNY) scale from 97% down to 67%.
The two published scales differ in one place. Queens College lists a single D for 60 to 66 and has no D-, while Johns Hopkins splits it into D (63 to 66) and D- (60 to 62). This calculator follows Johns Hopkins. The “letters only” option drops the plus and minus signs, so A is 90 and above, B is 80 to 89.99, C is 70 to 79.99, D is 60 to 69.99, and F is below 60. That grouping gives the same D range in both sources.
Worked examples
Example 1: 18 questions, 3 wrong. Points earned = 18 − 3 = 15. Percentage = 15 ÷ 18 × 100 = 83.33%. That reaches the 83 cutoff but not 87, so the grade is a B.
Example 2: 22 of 25. 22 ÷ 25 × 100 = 88.00%. That is at least 87 and below 90, so the grade is a B+.
Example 3: 27 of 40. 27 ÷ 40 × 100 = 67.50%. That is at least 67 and below 70, so the grade is a D+.
Common scores
| Score | Percent | Grade |
|---|---|---|
| 9 out of 10 | 90.00% | A- |
| 12 out of 15 | 80.00% | B- |
| 13 out of 15 | 86.67% | B |
| 14 out of 15 | 93.33% | A |
| 14 out of 20 | 70.00% | C- |
| 16 out of 20 | 80.00% | B- |
| 18 out of 20 | 90.00% | A- |
| 21 out of 25 | 84.00% | B |
| 22 out of 30 | 73.33% | C |
| 40 out of 50 | 80.00% | B- |
| 45 out of 50 | 90.00% | A- |
Questions and answers
What is 12 out of 15 as a grade?
12 out of 15 is 80%, which is a B- on the plus and minus scale and a B on a letters-only scale. Divide 12 by 15, then multiply by 100. The result sits exactly on the 80 cutoff, so it counts as the lowest B- score.
How do I find my grade if I only know how many I got wrong?
Subtract the wrong answers from the total to get the points you earned, then divide by the total and multiply by 100. For 3 wrong on an 18-question test, that is 15 earned, or 83.33%. Choose “Questions wrong” in the calculator to skip the subtraction.
Is 60% a passing grade?
On the scales cited here, 60% is the lowest percentage that earns a letter above F: a D- at Johns Hopkins and a D at Queens College, where D is the lowest passing grade for undergraduates. Courses and programs can set a higher minimum, so your syllabus or school policy decides.
Why does my teacher’s letter differ from this result?
Schools choose their own cutoffs. Some skip plus and minus grades, and some round before assigning a letter: the Johns Hopkins nursing policy rounds final course grades to the whole number, while this calculator compares the exact score. Check your cutoffs against the table above and ask which rounding rule applies.
Can a test score be above 100%?
Yes, when the test has extra credit and the points earned exceed the total. The calculator accepts that, shows the percentage above 100, and marks the letter as the top grade on the scale. Whether extra credit counts is your teacher’s decision.
Sources and review
- Johns Hopkins University School of Nursing, “Grading Policy”, Academic Catalogue 2026-27: e-catalogue.jhu.edu/nursing/policies/grading (percent score to letter grade conversion). Accessed 2026-11-01.
- Queens College, City University of New York, Academic Advising Center, “Academic and Grading Policies”, Suggested Grading Scale: qc.cuny.edu/aac/academic-and-grading-policies. Accessed 2026-11-01.
- The percentage definition (a part divided by the whole, times 100) is standard arithmetic. See Wikipedia, “Percentage”: en.wikipedia.org/wiki/Percentage. Accessed 2026-11-01.
Created by Dennis Norton. Calculations checked against an independent recomputation on 2026-11-01. Last reviewed: 2026-11-01.
Grading scales differ between schools. Check your teacher’s or school’s policy before relying on a result.
Related calculators
- Weighted grade calculator: combine several graded parts that count for different amounts.
- Grade curve calculator: see how a curve changes one score.
- All grade calculators: the full set in one place.