What this calculator does
This tool converts a grade point average (GPA) on the standard unweighted 4.0 scale back into the letter grade it represents. You enter a single GPA value between 0.0 and 4.0, and the calculator returns the closest letter grade (A, A-, B+, and so on), together with that letter's canonical grade-point value and its typical percentage range.
It is the reverse of a letter-grade-to-GPA lookup: instead of turning letters into points, it turns a point value into the letter a school would record.
How to use it
Type your GPA into the input box — for example 3.5 or 2.75 — and read the result. The large value is the matching letter grade. The table underneath shows the GPA you entered, the standard grade point for that letter, and the percentage band most US schools associate with it. Values are rounded to the nearest defined grade, so a GPA that falls between two letters is assigned to whichever letter is closest.
The formula explained
Each letter grade maps to a fixed grade-point value on the unweighted 4.0 scale: A = 4.0, A- = 3.7, B+ = 3.3, B = 3.0, B- = 2.7, C+ = 2.3, C = 2.0, C- = 1.7, D+ = 1.3, D = 1.0, D- = 0.7 and F = 0.0. To convert a GPA back to a letter, the calculator picks the letter L whose grade point g_L is nearest to your GPA:
$$ L = \operatorname{arg\,min}_L \; \bigl| \mathrm{GPA} - g_L \bigr| $$
The boundary between any two neighbouring grades is simply the midpoint of their grade points. If a is the lower grade point and c is the higher one, the cut-off is:
$$ b = \frac{a + c}{2} $$
For example, the line between A- (3.7) and A (4.0) sits at 3.85, so any GPA of 3.85 or above is reported as an A.
Worked example
Suppose your GPA is 3.6. The two closest grade points are B+ at 3.3 and A- at 3.7. The distance to A- is 0.1 while the distance to B+ is 0.3, so A- is nearer. Equivalently, 3.6 is above the A-/B+ midpoint of 3.15 but below the A/A- midpoint of 3.85, which also places it in the A- band. The calculator therefore reports a letter grade of A-, a standard grade point of 3.7, and a typical percentage range of 90-92%.
Frequently asked questions
Why does the grade point differ from the number I entered? The letter grade shows the standard grade point for that band, not your exact GPA. A GPA of 3.6 is closest to A-, whose canonical value is 3.7, so the grade point column reads 3.7 even though you entered 3.6.
How is A+ handled? On the standard unweighted 4.0 scale, A+ and A are both worth 4.0 grade points, so a GPA of 4.0 is reported as an A. Schools that use a 4.3 or higher scale for A+ fall outside this standard mapping.
Are the percentage ranges exact? No. The percentages shown follow the common US convention (for example 90-92% for A-), but individual schools set their own cut-offs, so treat them as a typical guide rather than a fixed rule.
