What this calculator does
A test grade is just the share of questions answered correctly, expressed as a percentage and then mapped onto a letter grade. It sounds trivial, but marking by hand invites arithmetic slips, especially on odd totals like 23 out of 27, and the letter-grade boundaries are easy to misremember under pressure.
This calculator applies the common ten-point letter scale (A, A-, B+ and so on down to F) used across most schools that grade this way. If your course curves marks, weights this test against others, or uses a different scale entirely, treat the percentage here as the raw input to that separate calculation rather than the final word.
The formula
Add any bonus or extra-credit points to the number answered correctly, divide by the total number of questions, and multiply by 100 to get the percentage. That percentage is then matched against the standard letter-grade bands.
| Term | Meaning |
|---|---|
| Score percentage | Correct answers (plus any bonus points) divided by total questions, expressed as a percentage. |
| Letter grade | The standard band the percentage falls into, from A+ at the top down to F. |
| Bonus points | Extra credit added on top of the questions answered, which can push the percentage above 100%. |
The inputs explained
| Field | What to enter |
|---|---|
| Questions answered correctly | The number of questions answered correctly, before any bonus points. |
| Total questions on the test | The total number of questions the test was marked out of. |
| Bonus / extra-credit points | Any extra-credit points awarded separately from the questions themselves. Leave at zero if there were none. |
When to use it
Marking a test quickly
Entering the raw correct count and total avoids doing the division and rounding by hand, especially on totals that do not divide evenly into 100.
Working out the effect of bonus questions
Comparing the score with and without bonus points shows exactly how much difference the extra credit made to the final letter grade.
Checking a grade boundary
When a result sits close to a letter-grade cutoff, such as 89% against a 90% threshold for an A-, it is worth confirming the exact percentage rather than estimating it.
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
What score and letter grade come from different results, out of 50 questions?
A fixed 50-question test, across a range of correct-answer counts.
How the same 45 correct answers score on tests of different length
A fixed 45 correct answers, marked against a range of total question counts.
Questions
What letter grade scale does this use?
The standard ten-point US scale: 97% and above is A+, down through A, A-, B+, B, B-, C+, C, C-, D+, D, D- and finally F below 60%. Schools that use a different scale, or a curve, will not match this exactly.
Can bonus points push a grade above 100%?
Yes. Bonus points are added straight to the correct-answer count before dividing by the total, so a strong result with bonus credit can score over 100%, which is why it still shows as A+ rather than anything higher.
Does this account for questions worth different point values?
No, this calculator assumes every question is worth the same amount. For a test with mixed point values, use total points earned in place of correct answers and total points possible in place of total questions.
How is this different from working out what I need on the final?
This calculator marks a single test that has already been sat. To work out what score is needed on an upcoming assessment to reach a target overall mark, use the grade needed on the final calculator instead.
To combine this result with other assessments into an overall course mark, see the grade needed on the final calculator, or the GPA calculator for a full weighted average across units.