Step 1: Convert each letter grade to grade points
On the standard 4.0 scale, each letter grade is worth a set number of grade points: A = 4.0, A− = 3.7, B+ = 3.3, B = 3.0, B− = 2.7, C+ = 2.3, C = 2.0, and so on down to F = 0.0.
Some schools use slightly different values (for example, awarding 4.33 for an A+ or using whole-letter grades only), so it's worth checking your school's official scale.
Step 2: Multiply grade points by credit hours
Courses aren't weighted equally — a 4-credit course counts more than a 1-credit one. Multiply each course's grade points by its credit hours to get its "quality points."
For example, an A (4.0) in a 3-credit course is worth 4.0 × 3 = 12 quality points.
Step 3: Add up and divide
Add all your quality points together, then divide by your total credit hours. That's your GPA.
Worked example: an A (4.0) in a 3-credit class, a B+ (3.3) in a 4-credit class, and an A− (3.7) in a 3-credit class gives (12 + 13.2 + 11.1) ÷ 10 = 3.63 GPA.
Why the credit weighting changes the answer
It is tempting to average the grade points directly — (4.0 + 3.3 + 3.7) ÷ 3 = 3.67 — but that is not your GPA. The correct credit-weighted answer above is 3.63. The gap opens up because the B+ sat in the 4-credit course, and heavier courses pull harder.
Flip the example to see how much this matters. Put the B+ in the 3-credit course and the A in the 4-credit one, and the same three letter grades produce a 3.70 instead. Identical transcript letters, meaningfully different GPA — which is why the credits column is not optional bookkeeping.
This is also the single most common mistake people make when checking a GPA by hand, and the reason a quick mental average usually disagrees with the registrar.
What counts, and what quietly doesn't
Pass/fail courses usually carry no grade points and are excluded from the calculation entirely — at UC Berkeley, for instance, Passed and Not Passed grades are explicitly excluded from all grade-point computations. A P cannot raise your GPA, and it cannot rescue it either.
Withdrawals normally post as a W and stay out of the GPA, though they still appear on your transcript. Incompletes typically sit outside the calculation until the grade resolves.
Transfer credit is the big one. Many schools accept the credits toward your degree but do not fold the grades into your institutional GPA, which means your transcript GPA and your 'all coursework' GPA can differ. Graduate programs often ask for the second one.
Semester GPA vs. cumulative GPA
A semester (or term) GPA covers just that term's courses. Your cumulative GPA runs across every graded course you have taken at the institution.
The practical consequence is that GPA gets harder to move over time. In your first semester with 15 credits, one A instead of a C swings your cumulative GPA by roughly 0.13. With 90 credits behind you, the same swap moves it by about 0.02. Nothing is wrong when this happens — it is just arithmetic, and it is worth knowing before you set a recovery target.
Check your school's actual scale
The values above are the most common US convention, not a universal standard. Rutgers awards no minus grades and sets B+ at 3.5 rather than 3.3. Texas A&M ignores plus and minus altogether for GPA purposes. The University of Florida awards no A+ and uses E instead of F.
Before you trust any number, confirm the scale your registrar actually uses — our per-university pages list the verified scale and cite the official source for each school.