Grade Calculator
Enter the points you earned and the points available. The calculator gives the percentage, the letter it falls in on the scale you select, the band boundaries either side of it, and how many more points the next letter up would have taken.
The letter is a policy, not a result
Converting points into a letter looks like one calculation and is really two. The first is arithmetic and nobody disagrees about it: points earned over points available, times a hundred. The second is a lookup into a table of bands, and that table was chosen by an institution rather than derived from anything. Two calculators can both be right and still disagree about a 92.
This tool keeps the halves visibly apart. It computes the percentage, then reports the letter under a scale you pick from a short list, names the scale it used in the working, and shows the boundaries on either side of the band you landed in. It also states how many more points the next letter would have taken — in points against your own total, which is the form that is actually actionable.
Grade boundaries encode a judgement about what a mark is worth, and institutions make that judgement differently. Some run a plus/minus scale where an A starts at 93 and an A− covers 90 to 92; others use whole letters with an A from 90. Some shift every boundary down a point or two. None of these is the correct one.
A calculator that hard-codes one table and presents its answer as the letter is asserting a policy it has no authority over. The reader has no way to tell that the answer would change under their own institution's table, because nothing on the page mentions that a table was involved.
So the scale is an input here and it is named in the output. That costs one dropdown and removes the entire class of error where a student reads a letter from a website and finds a different one on the transcript.
How to use this calculator
- Enter the points you earned The raw score, in whatever units the assessment uses — marks, points, questions correct. It does not need to be out of a hundred and it does not need to be a whole number.
- Enter the points available The maximum for the same assessment. This is the denominator, so it must be positive; a zero total would make the percentage undefined rather than infinite.
- Choose the grading scale Plus/minus is the more common in North American higher education; whole letters are more common in secondary schools and in courses that have deliberately coarsened their bands. If your syllabus lists boundaries, match whichever is closer and treat the letter as indicative.
- Read the band, not just the letter The working shows the lower bound of your band and the lower bound of the one above it. A percentage sitting a fraction below a boundary is the case worth knowing about, and the letter alone does not reveal it.
The formula, and where it comes from
percentage = points earned ÷ points possible × 100
The arithmetic is a proportion expressed per hundred. Nothing in it depends on the subject, the institution or the assessment type, which is why this half of the calculation is never in dispute.
Everything after it is a lookup. The percentage is compared against an ordered list of band minimums and the first band whose minimum it meets or exceeds is the answer. The list is data, not mathematics, and swapping the list changes the letter without changing a single arithmetic operation.
What each input means
- s Points earned — form field “Points earned”
- The mark achieved. Must be zero or greater. Scores above the total are permitted because extra credit exists, and they produce percentages above 100 rather than an error.
- t Points possible — form field “Points possible”
- The maximum available on the same assessment. Must be strictly positive — a total of zero has no percentage.
- — Grading scale — form field “Grading scale”
- Which band table to read the letter from. This is the input that makes the answer institution-specific, and the one most calculators hide.
Worked examples
Every number below is produced by the same calculation engine the tool above runs. Nothing here is typed by hand, so the walkthrough cannot drift from what you get when you enter the same values yourself.
A mark one point below a boundary
A test comes back at 76 out of 100. The student wants to know the letter and, more usefully, how close the next one was.
Inputs Points earned = 76, Points possible = 100, Grading scale = plus-minus
- Given 76 points out of 100
- Percentage 76 ÷ 100 × 100 = 76%
- Scale US 4.0 with plus/minus
- Band 73% ≤ 76% < 77% → C
- Next band C+ starts at 77%, which is 77 points — 1 more than you have
- Grade point C is worth 2 on this scale
- Caution Letter boundaries are an institutional convention, not arithmetic. Check the scale in your syllabus before relying on the letter.
Result 76% → C
76 percent lands in the C band, which on the plus/minus scale runs from 73 up to but not including 77. The letter is a C.
The next band starts at 77, which against a total of 100 is 77 points — one more than the student has. That is the number worth carrying into a conversation about a remark or a resubmission, and it is invisible if the tool reports only the letter.
The same percentage, two different letters
A 92 percent. Under plus/minus grading it is not an A, and under whole-letter grading it is. Nothing about the student's work differs between the two readings.
Inputs Points earned = 92, Points possible = 100, Grading scale = whole-letter
- Given 92 points out of 100
- Percentage 92 ÷ 100 × 100 = 92%
- Scale US 4.0, whole letters only
- Band 92% ≥ 90% → A
- Grade point A is worth 4 on this scale
- Caution Letter boundaries are an institutional convention, not arithmetic. Check the scale in your syllabus before relying on the letter.
Result 92% → A
On the whole-letter scale a 92 is a straight A, because the band runs from 90 to 100 with nothing between.
Switch the scale to plus/minus and the same 92 becomes an A−, worth 3.7 grade points rather than 4.0. Over a full course load that difference moves a GPA by a tenth or more, which is why the scale is worth checking rather than assuming.
Reading the result
The percentage
Exact and uncontroversial. It is reported before any band is applied so that it can be carried into a weighted average, entered into a different scale, or compared against a syllabus that quotes boundaries the tool does not offer.
The band
Shown as an interval rather than a single letter, because the interval is what tells you where you sit within the grade. A percentage at the bottom of a band and one at the top earn the same letter and are not the same result.
The points to the next letter
Expressed in the assessment's own points, not in percent. On a test marked out of 20 a one-percent gap is a fifth of a mark, which may not be a reachable score at all — a distinction that only appears once the boundary is converted back.
When you would use this
Checking a returned assessment
The most common use, and the one where the band boundaries matter most. A mark within a point of a boundary is worth a second look at the marking; a mark in the middle of a band is not.
Assumptions and limitations
What this calculator assumes
- The assessment is marked out of a fixed total and the score is on the same scale. Rubrics that map bands directly to letters without a numeric total are outside what this computes.
- The band table chosen resembles the institution's. The two offered are the widely used North American scales; an institution that shifts its boundaries will disagree at the edges.
Where it stops being the right tool
- It converts a single score. A course grade built from weighted categories has to be averaged first; this tool takes the result of that averaging rather than performing it.
- It does not know your institution's table. If your syllabus prints boundaries, those are authoritative and this page is indicative.
- Curved or norm-referenced grading is out of scope entirely, because in those systems the letter depends on the rest of the cohort rather than on the percentage.
Common mistakes
Assuming the calculator's scale is your institution's
Why it happens. Most grade calculators do not mention that a scale was used at all, so there is nothing to prompt the question.
How to avoid it. Check the syllabus once. The boundaries are usually printed in the first week's material, and a single check settles every subsequent conversion for that course.
Averaging percentages across assessments of different sizes
Why it happens. It is the obvious thing to do and it is right when everything is weighted equally, which is sometimes true.
How to avoid it. Weight each percentage by the points or the category weight it carries. A 100 percent on a five-point quiz does not offset a 60 on a hundred-point exam.
Frequently asked questions
What percentage do I need for an A?
90 on the whole-letter scale, 93 on the plus/minus scale where 90 to 92 is an A−. The gap between those two answers is why the scale is an input on this page.
Can the percentage exceed 100?
Yes, and it is not treated as an error. Extra credit produces scores above the total, and the result simply lands in the highest band.
Does a 79.5 round up to an 80 and become a B−?
Not here. Bands are applied to the exact percentage, so 79.5 is a C+. Some gradebooks round to a whole percent before applying bands, which would give a different answer — worth checking if you are at an edge.