The standard 4.0 scale
This is the plus/minus scale used by most US colleges and by high schools that record pluses and minuses. The percentage bands in the third column are the most common convention, not a national standard — see the section below on why that matters.
| Letter | Grade points | Typical percentage |
|---|---|---|
| A+ | 4.0 | 97–100 |
| A | 4.0 | 93–96 |
| A− | 3.7 | 90–92 |
| B+ | 3.3 | 87–89 |
| B | 3.0 | 83–86 |
| B− | 2.7 | 80–82 |
| C+ | 2.3 | 77–79 |
| C | 2.0 | 73–76 |
| C− | 1.7 | 70–72 |
| D+ | 1.3 | 67–69 |
| D | 1.0 | 63–66 |
| D− | 0.7 | 60–62 |
| F | 0.0 | 0–59 |
The 4.3 scale
Identical to the table above with one change: an A+ is worth 4.3 rather than being capped at 4.0. Every other row is the same.
It matters more than it looks. On a 4.0 scale, a student with straight A+ grades and a student with straight A grades both have a 4.0 and are indistinguishable. On a 4.3 scale the first has a 4.3. Institutions split roughly into three groups: those that do not award A+ at all, those that award it but cap it at 4.0, and those that let it reach 4.3. Which group your school is in is written in your catalogue and is not something you can infer from your transcript.
The 5.0 weighted scale
Used by many US high schools to reward harder course loads. Take the 4.0 values above and add a bump for course level:
| Course level | Common bump | An A is worth | A B is worth |
|---|---|---|---|
| Regular | +0.0 | 4.0 | 3.0 |
| Honours | +0.5 | 4.5 | 3.5 |
| AP or IB | +1.0 | 5.0 | 4.0 |
+0.5 and +1.0 are the most common values. They are not universal: some districts add 0.5 to everything advanced, some add nothing and report unweighted only, some cap the weighted GPA at 4.5, and dual-enrolment courses are treated inconsistently even within a single district.
Straight letters, without plus and minus
Plenty of schools record only A, B, C, D and F. On that system every A is 4.0 and every B is 3.0 — there is no 3.7 or 3.3.
This is not a rounding difference, it is a different grading system, and it produces measurably different GPAs from identical work. A transcript full of A− and B+ grades comes out around 3.5 with plus/minus and 3.5 without it too — but a transcript of A− grades alone is 3.7 with plus/minus and 4.0 without. Students moving between schools notice this and are usually told it is a mistake. It is not.
Why these tables disagree with each other
Search for a grade conversion table and you will find versions that put a B at 83–86, at 80–86, and at 84–86. None of them is wrong, because there is no national standard tying percentages to letters in the United States. Each institution sets its own bands, publishes them in a catalogue or handbook, and applies them consistently within its own walls.
What is standard is the grade-point value once the letter is assigned. An A− is 3.7 essentially everywhere that uses plus/minus grading. The instability is entirely on the percentage side, which is exactly the side people most want a definitive table for.
The practical consequence: a percentage-to-GPA conversion found online tells you what a typical school would do, not what your school does. If a boundary matters to you — and at 89.5% it usually does — your institution's published scale is the only source that counts. Ours is offered as the common convention and labelled as such.
What the bands mean in practice
These are common conventions across US institutions, not statements about any particular school and not advice about your situation.
- 4.0 — the unweighted maximum. Straight As.
- 3.5+ — the usual Dean's List and honour-roll threshold, though institutions set it anywhere from 3.25 to 3.7.
- 3.0 — a B average. A common floor for scholarship renewal and for many graduate programme applications.
- 2.0 — the usual line for good academic standing. Below it, most institutions place a student on academic probation.
- Above 4.0 — only possible on a weighted scale, and only meaningful alongside the scale it was computed on. A 4.3 means nothing until you know whether it came off a 4.3 or a 5.0 system.
Converting a percentage to a GPA
Two steps, and the first one is the one people skip. Convert the percentage to a letter using your school's bands, then convert the letter to grade points using the table above. Going straight from percentage to grade points with a formula — dividing by 25, or similar — produces numbers that no registrar would recognise.
Once you have letters for every course, the GPA calculator will weight them by credits and return both the weighted and unweighted figures.