How to Calculate Your GPA
A grade point average turns letter grades into one number. The basic idea is the same everywhere: convert each grade to points, weight by credits if your school uses them, and divide. What changes between schools is the scale and whether harder classes count extra.
Step 1: convert grades to points
| 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+ / D / D- | 1.3 / 1.0 / 0.7 |
| B- | 2.7 | F | 0.0 |
This is the most common 4.0 plus/minus scale. Some schools give A+ a 4.3, and some do not use plus or minus grades at all. Your school's handbook has the official table.
Unweighted GPA: a simple average
Many high schools give each class equal weight. Add the points and divide by the number of classes. English A (4.0), Algebra B (3.0), History A (4.0), Chemistry B (3.0) and Spanish C (2.0) add up to 16.0. Divide by 5 and the unweighted GPA is 3.20.
Weighted GPA: extra points for harder classes
Many high schools add a bonus for honors, AP or IB classes. A common convention is +0.5 for honors and +1.0 for AP or IB, so an A in AP can count as 5.0. These are conventions, not universal rules: some schools add +1.0 for honors too, some cap the bonus, and some colleges recalculate your GPA without any bonuses.
Using that common convention on the example above, if Algebra was honors and Chemistry was AP: English 4.0, Algebra 3.5, History 4.0, Chemistry 4.0, Spanish 2.0. The total is 17.5, and the weighted GPA is 3.50.
College GPA: weighted by credit hours
Colleges weight each grade by its credit hours. Multiply points by credits to get quality points, add them, and divide by total credits.
| Course | Credits | Grade | Quality points |
|---|---|---|---|
| Biology | 4 | B (3.0) | 12.0 |
| Calculus | 4 | A (4.0) | 16.0 |
| Writing | 3 | A- (3.7) | 11.1 |
| PE | 1 | C (2.0) | 2.0 |
| Total | 12 | 41.1 |
41.1 ÷ 12 = 3.425. The GPA Calculator does this credit-hour math for you. To include an honors or AP bonus there, use your school's bonus as part of the grade points by hand, since bonus rules differ.
Cumulative GPA and common mistakes
To combine semesters, add all quality points and divide by all credits. Do not average the two semester GPAs: a 4.0 over 6 credits and a 3.0 over 15 credits is 3.29 overall, not 3.5.
- Counting pass/fail or withdrawn classes. Most schools leave them out of GPA.
- Forgetting repeated courses. Many schools replace the old grade instead of averaging both.
- Mixing scales. A weighted 4.3 and an unweighted 3.9 cannot be compared directly.