How to calculate your GPA, step by step
A GPA is a credit-weighted average of your grades. Three steps get you there, and the only thing that changes between schools is the number each letter grade is worth.
Step 1: turn each letter grade into grade points
On the most common US 4.0 scale an A is 4.0, a B is 3.0, a C is 2.0, a D is 1.0 and an F is 0. Schools that use plus and minus grades usually put A− at 3.7, B+ at 3.3, B− at 2.7 and so on, but not all of them do. At MIT, for example, the plus and minus modifiers “appear only on internal grade reports” and “are not used in calculating term or cumulative grade-point averages.” Some schools give an A+ 4.3, others cap it at 4.0. Check the grade table in your own catalog before you start — how to turn letter grades into grade points covers the common variations.
Step 2: multiply by credits
Each course's grade points are multiplied by its credit hours. The result is called quality points. A 4-credit course counts four times as much as a 1-credit lab — see why credit weighting exists.
Step 3: divide total quality points by total credits
Add up the quality points, add up the credits, and divide.
| Course | Credits | Grade | Points | Quality points |
|---|---|---|---|---|
| English | 3 | A | 4.0 | 12.0 |
| Calculus | 4 | B+ | 3.3 | 13.2 |
| Chemistry | 4 | B | 3.0 | 12.0 |
| History | 3 | A− | 3.7 | 11.1 |
| Total | 14 | 48.3 |
GPA = 48.3 ÷ 14 = 3.45. The college GPA calculator does exactly this with any scale; high school students can use the high school GPA calculator, where each class usually counts equally.
Cumulative GPA is not an average of semester GPAs
This is the most common mistake. If you earned a 3.0 over 12 credits in one semester and a 4.0 over 18 credits in the next, your cumulative GPA is (12 × 3.0 + 18 × 4.0) ÷ 30 = 108 ÷ 30 = 3.60 — not 3.50. The heavier semester counts for more. The cumulative GPA calculator keeps the credits attached to each term so this cannot go wrong.
Weighted and unweighted GPA
An unweighted GPA uses the plain scale, so the top is 4.0. A weighted GPA, used mostly in high schools, adds a bonus for harder courses — commonly +0.5 for honors and +1.0 for AP or IB — so it can exceed 4.0. The bonus is set by each school district, not nationally. Use the weighted GPA calculator and set the bonus your school uses.
Grades that usually do not count
Pass/fail, withdrawal (W) and incomplete grades normally earn no grade points and are left out of both the quality points and the credits. Transfer credit is often recorded without a grade. Rules differ, so check before you drop a course from the calculation — see pass/fail and satisfactory grades and withdrawal grades.
Key takeaways
- GPA = total quality points ÷ total credits, where quality points = grade points × credits.
- The value of each letter grade is set by your school; plus/minus and A+ handling vary.
- Cumulative GPA is recalculated from all credits, never averaged from semester GPAs.
- Weighted GPA adds a school-set bonus for honors, AP and IB courses.