Knowing how to calculate GPA yourself is useful. You can double-check your transcript, plan next semester, and catch mistakes before they cost you a scholarship. The math is simpler than it looks: it’s a weighted average where credit hours are the weights.
If you only need the number, our free GPA calculator does it in seconds. If you want to understand what’s happening behind the scenes, read on.
The GPA formula
GPA = total quality points ÷ total credit hours attempted
“Quality points” is just the grade’s point value multiplied by the credits for that class. A 4-credit course with a B (3.0) earns 12 quality points.
Step 1: Convert each letter grade to points
Most U.S. high schools and colleges use this 4.0 scale:
| Grade | Points | Grade | Points |
|---|---|---|---|
| A / A+ | 4.0 | C+ | 2.3 |
| A- | 3.7 | C | 2.0 |
| B+ | 3.3 | C- | 1.7 |
| B | 3.0 | D+ | 1.3 |
| B- | 2.7 | D | 1.0 |
| F | 0.0 |
Check your student handbook. A few schools give an A+ 4.33, and some don’t use plus/minus grades at all.
Step 2: Multiply points by credit hours
Write down each course’s credits next to its grade points and multiply. This step is what makes a 4-credit lab science count more than a 1-credit seminar.
Step 3: Add up quality points and credits
Total the quality points column, then total the credits column. Only include courses that carry a letter grade. Pass/fail classes, withdrawals and audits normally stay out.
Step 4: Divide
Divide total quality points by total credits and round to two decimals. That’s your GPA.
Worked example: one college semester
| Course | Grade | Points | Credits | Quality points |
|---|---|---|---|---|
| Statistics | A- | 3.7 | 3 | 11.1 |
| Chemistry I | B | 3.0 | 4 | 12.0 |
| World History | A | 4.0 | 3 | 12.0 |
| Spanish II | B+ | 3.3 | 3 | 9.9 |
| Chemistry Lab | A | 4.0 | 1 | 4.0 |
| Total | 14 | 49.0 |
49.0 ÷ 14 = 3.50. Notice how the B in 4-credit Chemistry pulls the average down more than the B+ in 3-credit Spanish would on its own.
How to calculate weighted GPA
High schools that weight GPA add bonus points before multiplying by credits. A common system adds 0.5 for Honors and 1.0 for AP, IB or dual-enrollment classes. So an A in AP Biology becomes 5.0, and a B in Honors English becomes 3.5. Everything else in the formula stays the same. Many schools only give the bonus for grades of C or better, so check your school’s policy.
How to calculate cumulative GPA
Cumulative GPA isn’t the average of your semester GPAs. It’s every quality point you’ve earned divided by every credit you’ve attempted. If you know your old GPA and credits, use this shortcut:
New cumulative GPA = (old GPA × old credits + new quality points) ÷ (old credits + new credits)
Example: a 3.20 over 45 credits, plus a 3.60 semester over 15 credits, gives (144 + 54) ÷ 60 = 3.30. Averaging 3.20 and 3.60 would give 3.40, which is wrong, because the earlier semesters carry three times the credits.
How to calculate GPA without credits
Middle schools and some high schools don’t assign credit hours. In that case, give every class a weight of 1. Your GPA is simply the average of your grade points. Five classes with A, A, B+, B and A- work out to (4 + 4 + 3.3 + 3 + 3.7) ÷ 5 = 3.60.
Common mistakes to avoid
- Averaging semester GPAs instead of combining credits. This overweights short semesters.
- Counting pass/fail or withdrawn courses as zeros. Most schools exclude them.
- Mixing weighted and unweighted points in the same calculation.
- Forgetting repeated courses. If your school replaces the old grade, remove the first attempt’s credits too.
- Rounding too early. Keep full decimals until the final step.
Check your work instantly
Once you understand the steps, let the tool do the arithmetic. Enter your classes into our GPA calculator to get your semester and cumulative GPA, switch to weighted mode for AP and Honors classes, and use the target planner to see what you need next term. To improve the number itself, read How to Raise Your GPA.