Letter Grade Calculator
Convert a percentage score into a letter grade and GPA point value.
Results update as you type.
About this calculator
A letter grade calculator maps a percentage onto a letter scale and shows the grade point value that letter carries. On the standard plus/minus scale 90–100 is an A, 80–89 a B, 70–79 a C and so on, with plus and minus bands inside each ten-point range (for example 87–89 is a B+ and 80–82 a B-); the simple scale drops the pluses and minuses so the whole 90s are a plain A.
Worked example: a score of 91% lands in the 90–92 band, which is an A- worth 3.7 grade points on the 4.0 scale; the same 91% on the simple scale is just an A worth 4.0. A full reference table lists every band, its percentage range and its GPA value.
The GPA points are what feed into your grade point average, so this tool is the bridge between a raw class percentage and the number that appears on a transcript. Students use it to translate a syllabus’s cut-offs into a letter, and to see how close a borderline score sits to the next letter up.
Frequently asked questions
What percentage is an A?
On the common US scale an A is 93–100%, an A- is 90–92%, and 97% and above is often labelled A+. Below that, each ten-point band drops a letter: 80s are B, 70s are C, 60s are D and below 60 is F. The simple scale treats the whole 90s as a plain A.
How do letters convert to GPA points?
An A is 4.0, B is 3.0, C is 2.0, D is 1.0 and F is 0.0, with a minus subtracting about 0.3 and a plus adding about 0.3 (an A+ is still capped at 4.0 at most schools).
What is the difference between the plus/minus and simple letter grade scales?
The plus/minus scale splits each letter into three bands — B-, B and B+ — and gives each its own GPA value, so it distinguishes an 82% from an 88%. The simple scale uses only A, B, C, D and F, treating every score in the 80s as the same B. Pick whichever your school uses.
What is the lowest passing grade?
At most schools 60% (a D-) is the minimum passing mark, though many programmes require a C (70%) or higher for a course to count toward a major or prerequisite. Below 60% is an F, which earns zero GPA points.
Is 89% an A or a B?
On the standard scale 89% is a B+ — an A does not begin until 90% (an A-). It is a common borderline, which is why the reference table shows each band’s exact cut-off so you can see how close a score sits to the next letter.
How much is an A+ worth on a 4.0 scale?
At most US schools an A+ still counts as 4.0 — the same as an A — because the unweighted scale caps there. A few institutions award 4.3 for an A+, but this calculator uses the common 4.0 cap.
API — use this calculator from code
Call this calculator as a free JSON endpoint — no key required. Send the field values below as query parameters or JSON. Read the full API docs →
Endpoint
GET https://calculator.free/api/v1/letter-grade/curl
curl "https://calculator.free/api/v1/letter-grade/?score=90&scale=plusminus"JavaScript fetch()
const r = await fetch(
"https://calculator.free/api/v1/letter-grade/?" + new URLSearchParams({
"score": "90",
"scale": "plusminus"
}));
const data = await r.json();
console.log(data.results);Results are estimates for general guidance only, not financial, medical or tax advice.