On the most common unweighted US GPA scale, A = 4.0, B = 3.0, C = 2.0, D = 1.0, and F = 0.0 grade points. A course grade of A- on a school that uses plus/minus modifiers is typically 3.7, not a full 4.0, because each plus or minus commonly shifts the base value by 0.3 points — but that plus/minus shift is a school-specific policy choice, not part of the base 4.0 scale itself.
What is the worked GPA for four graded courses?
A student earns A- in a 3-credit course, B+ in a 4-credit course, A in a 3-credit course, and C+ in a 2-credit course, on a school that uses the common 0.3-point plus/minus shift. Convert each grade to points: A- = 3.7, B+ = 3.3, A = 4.0, C+ = 2.3. Multiply each by its credit count: 3.7 × 3 = 11.1, 3.3 × 4 = 13.2, 4.0 × 3 = 12.0, 2.3 × 2 = 4.6. Summing the grade points gives 11.1 + 13.2 + 12.0 + 4.6 = 40.9, and summing the credits gives 3 + 4 + 3 + 2 = 12. Dividing: 40.9 ÷ 12 = 3.408, which rounds to a 3.41 GPA for that term.
How do I convert letter grades to GPA points myself?
Convert each letter grade to its point value on the school’s published scale, multiply each by the credit hours (or units) for that course, add all the resulting grade-point totals together, then divide by the total credit hours attempted. The GPA calculator performs this credit-weighted division directly; the grade calculator works the other direction, finding what score on a single assignment or exam is needed to reach a target grade.
How do I check a computed GPA?
A quick plausibility check: the resulting GPA must fall between the lowest and highest individual grade point value entered, and it should sit closer to whichever grade carried more credit hours. In the worked example, the four grade points (3.7, 3.3, 4.0, 2.3) range from 2.3 to 4.0, and the computed 3.41 GPA falls inside that range, pulled toward the higher end because three of the four courses (10 of 12 credits) carried a B+ or better. A GPA computed outside the range of the individual grade points entered signals an arithmetic error, most often a credit-hour figure applied to the wrong course.
What mistakes produce a wrong GPA?
The most common mistake is averaging the raw grade-point values without weighting by credit hours — treating (3.7 + 3.3 + 4.0 + 2.3) ÷ 4 = 3.325 as the answer instead of the credit-weighted 3.41 — which understates the GPA whenever the higher grades carry more credit than the lower ones, as they do here. A second mistake is applying a plus/minus shift that a particular school does not actually use; some institutions report only whole-letter grades (A, B, C, D, F) with no A- or B+ distinction, so a computed 3.7 or 3.3 would not match that school’s own transcript at all. A third is including a pass/fail, audit, or transfer-credit course that the school explicitly excludes from GPA — those credits still count toward graduation but not toward the grade-point average.
What does this conversion not decide?
This conversion describes the common unweighted 4.0 scale and the common 0.3-point plus/minus shift, both widely used but not universal. It does not apply directly to a 5.0 weighted scale that adds extra points for honors or Advanced Placement courses, to a percentage-based scale used outside GPA reporting, or to international grading systems that use entirely different point ranges. A specific school’s registrar or catalog is the authority on which scale and which plus/minus policy actually applies to a given transcript.
Source for the external fact
The U.S. National Center for Education Statistics describes the standard four-point scale used in its High School Transcript Study — A equals four points, B equals three points, C equals two points, D equals one point, and F equals zero points, with GPA found by dividing total grade points earned by total credits attempted — in its GPA methodology page.
A reference table for the unweighted 4.0 scale with plus/minus shifts
The same fixed 0.3-point shift produces every row; only the base letter and modifier change.
| Letter grade | Grade points |
|---|---|
| A+ | 4.0 (capped) |
| 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 |
| F | 0.0 |
A+ is commonly capped at the same 4.0 as a plain A, rather than allowed to reach 4.3, specifically because the unweighted scale has no value above 4.0 to shift up to; a small number of schools do allow a 4.3 A+ on their own published scale, which is exactly why the base scale alone cannot answer the question without checking the issuing school’s policy.
A second worked example: a term that excludes a pass/fail course
A student takes Chemistry (B, 3 credits), Spanish (A-, 3 credits), Physical Education (Pass/Fail, 1 credit), and Economics (C+, 3 credits), at a school that excludes pass/fail grades from GPA entirely. Grade points: B = 3.0 × 3 = 9.0; A- = 3.7 × 3 = 11.1; Pass/Fail contributes no grade points and its 1 credit is not counted in the GPA denominator (though it still counts toward graduation credit); C+ = 2.3 × 3 = 6.9. Total grade points: 9.0 + 11.1 + 6.9 = 27.0. Total GPA-eligible credits: 3 + 3 + 3 = 9 (the pass/fail credit is excluded). GPA: 27.0 ÷ 9 = 3.00 exactly — a clean result that would be wrong (27.0 ÷ 10 = 2.70) if the pass/fail credit hour were mistakenly folded into the denominator.
Why a 4.0-scale GPA cannot be compared directly across two different schools
Two students each reporting a 3.5 GPA may have taken different courses graded on different internal scales — one school’s plus/minus policy, grading curve, and course difficulty are not encoded anywhere in the single 3.5 figure. A weighted 5.0-scale GPA, which adds roughly a full point for an honors or AP course grade, produces numbers that look similar in magnitude to an unweighted 4.0 GPA but are not the same measurement; a 4.2 on a weighted scale and a 3.8 on an unweighted scale cannot be ranked against each other without first confirming which scale each figure uses.
The transcript credit-hour trap: 120 instructional hours per Carnegie unit
US high school and college transcripts standardize a single course credit using the Carnegie unit, commonly defined as roughly 120 instructional hours for a full-year course; a semester-long course is typically worth half a full-year credit. A student’s transcript that lists course credit as “0.5” rather than “1” for a single-semester class must use that 0.5 figure as the weight in the credit-weighted average described above — using “1” for every course regardless of its actual length overstates the contribution of short courses and understates full-year ones.
A worked example on a weighted 5.0 scale, and why it is not comparable to the unweighted figures above
A school that adds a full extra point for Advanced Placement (AP) courses reports a different scale entirely. A student takes AP Biology (A, 4 credits, weighted to 4.0 + 1.0 = 5.0 points), English (B+, 3 credits, unweighted at 3.3 points), and Precalculus (A-, 3 credits, unweighted at 3.7 points). Grade points: AP Biology 5.0 × 4 = 20.0; English 3.3 × 3 = 9.9; Precalculus 3.7 × 3 = 11.1. Total grade points: 20.0 + 9.9 + 11.1 = 41.0. Total credits: 4 + 3 + 3 = 10. Weighted GPA: 41.0 ÷ 10 = 4.10 — a figure above the unweighted scale’s own maximum of 4.0, which is only possible because the AP bump adds points beyond that ceiling. This 4.10 weighted GPA and the 3.41 unweighted GPA from the first worked example above are not two measurements of comparable difficulty; they are answers on two different scales entirely, and ranking students by one when their schools use the other compares numbers, not achievement.
Related calculators
Compute a full-term GPA directly with the GPA calculator, work out a needed exam score with the grade calculator, and combine several terms into one cumulative figure with the cumulative GPA guide.