How to Calculate Your GPA: Weighted and Unweighted
A grade point average is the credit-weighted average of your grades on a points scale, usually 4.0. This page shows how to convert letter grades to points, weight them by credit hours, work a full semester example, and tell the difference between weighted and unweighted GPAs.
The 4.0 Scale
Most US schools use a 4.0 scale, where each letter grade has a numeric value: A = 4.0, B = 3.0, C = 2.0, D = 1.0, F = 0.0. Your GPA is the average of these points across your courses, adjusted for how much each course counts.
The scale exists because raw percentages vary between teachers and institutions. Standardizing achievement into a few values lets colleges compare students from thousands of different schools.
Honors and Advanced Placement courses often earn points above 4.0 (see weighted GPA below), and many schools add pluses and minuses for finer resolution.
Converting Letter Grades to Grade Points
Every grade needs a numeric equivalent before you can average. A common plus/minus table:
- 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
- F = 0.0
Why Credit Hours Matter
If every course carried equal weight you could simply average the grade points. But a four-credit chemistry course demands more than a one-credit seminar, so it should count more. Registrars handle this with quality points:
Quality Points (per course) = Grade Points × Credit Hours
GPA = Total Quality Points ÷ Total Credit Hours
A strong grade in a four-credit course lifts your GPA more than the same grade in a one-credit elective.
A Worked Example
A semester of five courses:
- English Composition: B+ (3.3), 3 credits
- Calculus I: A− (3.7), 4 credits
- Introduction to Psychology: A (4.0), 3 credits
- General Chemistry: C+ (2.3), 4 credits
- Public Speaking: B (3.0), 2 credits
- English: 3.3 × 3 = 9.9
- Calculus: 3.7 × 4 = 14.8
- Psychology: 4.0 × 3 = 12.0
- Chemistry: 2.3 × 4 = 9.2
- Public Speaking: 3.0 × 2 = 6.0
GPA = 51.9 ÷ 16 = 3.24 (rounded to two decimals). The four-credit chemistry C+ pulled the average down more than the two-credit B in public speaking, even though C+ is only one step lower: that is the credit-hour weighting at work.
The GPA Calculator takes the two totals, total grade (quality) points and total credit hours, and divides them, capping the result at 4.0 or, if you choose the weighted scale, 5.0. Add up the quality points as above, then enter 51.9 and 16 to get 3.24.
Weighted vs. Unweighted GPA
Everything above is an unweighted GPA, which caps every course at 4.0 regardless of difficulty. A weighted GPA rewards harder classes by adding points for honors, Advanced Placement or International Baccalaureate courses.
Under a typical weighted system, an honors course adds 0.5 to each grade point and an AP or IB course adds 1.0, so an A in AP Biology counts as 5.0 and a B in an honors course as 3.5. This is why some high school GPAs exceed 4.0.
The two figures serve different purposes. Weighted GPA signals that you took rigorous coursework; unweighted GPA gives a cleaner comparison of raw performance. Colleges often recalculate applicants' GPAs with their own formulas, so calculate both.
Cumulative GPA Across Semesters
Cumulative GPA pools all quality points ever earned and divides by all credit hours ever attempted. You do not average the semester GPAs, because semesters carry different numbers of credits.
If your first semester produced 51.9 quality points across 16 credits and your second produced 45.0 across 15, your cumulative GPA is (51.9 + 45.0) ÷ (16 + 15) = 96.9 ÷ 31 ≈ 3.13.
If a single course is still in progress, the Final Grade calculator tells you the exam score you need, given your current grade and the final's weight, to reach the course grade (and so the grade points) you are aiming for.
Early on, each grade moves the cumulative average a lot. With dozens of credits banked, even a perfect semester nudges it only slightly, which is worth knowing when you judge whether recovery from a weak term is realistic.
Related guide: how to calculate percentages.