To calculate your GPA, convert each course’s final grade into grade points (on the common US scale A = 4.0, B = 3.0, C = 2.0, D = 1.0, F = 0.0), multiply the points by the course’s credits, add those products, and divide by the total credits. For example, grades of A-, B, C+ and A in courses worth 3, 4, 4 and 3 credits give 44.3 points ÷ 14 credits = a 3.16 GPA.
If you want the background first (what GPA is, term vs. cumulative, why colleges recalculate it), read what GPA is. This page is the hands-on version: you start from the grades on your report card and finish with a number.
What do you need before you start?
- Your final grade in each course for the term, as a percentage, a number or a letter.
- The credits (credit hours) of each course. They are on your transcript or in the course catalog. In many high schools every course carries the same credit; then you can treat each as 1.
- Your school’s grading scale, the table that tells you which percentage earns which letter. Schools publish it in the student handbook or catalog. The cutoffs below are one real example, not a universal rule.
We will use one semester of four courses plus a pass/fail PE class:
| Course | Final grade | Credits |
|---|---|---|
| English Composition | 91% | 3 |
| Calculus | 85% | 4 |
| Chemistry | 78% | 4 |
| Psychology | 95% | 3 |
| Physical Education | Pass | 1 |
Step 1. Convert percentage grades to letter grades
Look up each percentage on your school’s scale. This example uses the plus/minus scale published by Sacred Heart University:
| Percentage | Letter | Percentage | Letter |
|---|---|---|---|
| 93–100 | A | 77–79 | C+ |
| 90–92 | A- | 73–76 | C |
| 87–89 | B+ | 70–72 | C- |
| 83–86 | B | 67–69 | D+ |
| 80–82 | B- | 60–66 | D |
| 0–59 | F |
So English 91% is an A-, Calculus 85% a B, Chemistry 78% a C+ and Psychology 95% an A. If your report card already shows letters, skip this step. If you only have assignment scores, the grade calculator turns scores and category weights into a course percentage and a letter.
Do not average the percentages and convert once at the end. GPA is calculated from each course’s letter. Here the credit-weighted average percentage is (91 × 3 + 85 × 4 + 78 × 4 + 95 × 3) ÷ 14 ≈ 86.4%, which is a B and would suggest a 3.0, but the real GPA below is 3.16.
Step 2. Convert letter grades to grade points
On the usual 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, F 0.0. Some colleges use thirds instead (A- 3.67, B+ 3.33); the US grading system guide shows both versions and how much they change the result.
Our courses become 3.7, 3.0, 2.3 and 4.0 points.
Leave out marks without grade points. Pass/no pass, W (withdrawal), I (incomplete) and audit have no point value, so the course and its credits stay out of the GPA. An F is different: it counts as 0.0 points with full credits, which is why it pulls a GPA down so much.
Step 3. Multiply grade points by credits
| Course | Grade | Points | Credits | Points × credits |
|---|---|---|---|---|
| English Composition | A- | 3.7 | 3 | 11.1 |
| Calculus | B | 3.0 | 4 | 12.0 |
| Chemistry | C+ | 2.3 | 4 | 9.2 |
| Psychology | A | 4.0 | 3 | 12.0 |
| Physical Education | Pass | — | (1) | not counted |
The products are called quality points or grade points.
Step 4. Add up the points and the credits
Total points: 11.1 + 12.0 + 9.2 + 12.0 = 44.3. Total credits with a letter grade: 3 + 4 + 4 + 3 = 14. The 1-credit pass is not included.
Step 5. Divide total points by total credits
44.3 ÷ 14 = 3.164…, so the semester GPA is 3.16.
A common mistake is to include the pass/fail credit: 44.3 ÷ 15 = 2.95, which understates the GPA by 0.21. Another is to ignore credits and average the four point values: (3.7 + 3.0 + 2.3 + 4.0) ÷ 4 = 3.25, too high, because the 4-credit C+ in Chemistry counts more than the 3-credit courses.
Registrars round or truncate GPAs in different ways, so your transcript may differ from a hand calculation in the last decimal.
How do you calculate a cumulative GPA?
Do not average your semester GPAs. Work with points and credits:
- Multiply your current cumulative GPA by the credits it covers. A 3.50 over 30 credits is 3.50 × 30 = 105.0 points.
- Add the new semester’s points: 105.0 + 44.3 = 149.3.
- Add the credits: 30 + 14 = 44.
- Divide: 149.3 ÷ 44 = 3.39.
Averaging the two GPAs, (3.50 + 3.16) ÷ 2 = 3.33, would be wrong, because the earlier 30 credits carry more than twice the weight of this semester.
How do you calculate a weighted GPA in high school?
Use the same five steps, but add the bonus for course level to each passing grade before multiplying by credits. A common setup is +0.5 for honors and +1.0 for AP or IB; your school may use different values or no weighting at all.
If Chemistry in the example were an AP course, its C+ would count as 2.3 + 1.0 = 3.3 points, the total would rise by 1.0 × 4 = 4.0 to 48.3, and the weighted GPA would be 48.3 ÷ 14 = 3.45, while the unweighted GPA stays 3.16. Colleges often look at the unweighted figure or recalculate it with their own rules; what counts as a good GPA explains how admissions offices compare them.
Can you check the result faster?
Yes. Enter each course’s letter grade, credits and level in the GPA calculator and it does steps 2–5 for you, including weighted GPA. Its Target Grade mode works the cumulative formula backward: tell it your current GPA and credits, your goal and next term’s credits, and it shows the average you need next term.
Sources
- Sacred Heart University, Grading Policy (percentage scale, quality points, P/W/I): https://www.sacredheart.edu/offices—departments-directory/registrar/grading-policy/
- College Board BigFuture, “How to Convert Your GPA to a 4.0 Scale”: https://bigfuture.collegeboard.org/plan-for-college/get-started/how-to-calculate-gpa-4.0-scale