To figure out your GPA, you convert each letter grade to a number on a 4.0 scale, then average those numbers. If your courses carry different credit hours, you weight each grade by its credits before averaging. The math is straightforward once you know the point values, and the same basic method works for high school and college.
The 4.0 Scale
Every GPA calculation starts by turning letter grades into numbers. Here’s the standard 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
- F: 0.0
Some schools use a simplified version that doesn’t distinguish plus and minus grades. In that system, any A is 4.0, any B is 3.0, any C is 2.0, any D is 1.0, and an F is 0.0. Check your transcript to see which version your school uses.
Simple GPA for Equal-Credit Classes
If all your classes are worth the same number of credits (common in high school), the calculation is simple: convert each grade to its point value, add them up, and divide by the number of classes.
Say you have five classes this semester with grades of A, B+, A-, B, and C+. That translates to 4.0, 3.3, 3.7, 3.0, and 2.3. Add those together to get 16.3, then divide by 5. Your GPA is 3.26.
Weighted GPA With Credit Hours
In college, courses carry different numbers of credit hours, and a 4-credit class should count more heavily than a 1-credit class. The formula accounts for this by using what your school may call “quality points” or “honor points.”
For each course, multiply the grade’s point value by the number of credit hours. Then add up all those products and divide by your total credit hours. Here’s an example semester:
- Biology (4 credits), grade A: 4.0 × 4 = 16.0
- English (3 credits), grade B+: 3.3 × 3 = 9.9
- History (3 credits), grade B: 3.0 × 3 = 9.0
- Art (2 credits), grade A-: 3.7 × 2 = 7.4
- Lab (1 credit), grade A: 4.0 × 1 = 4.0
Total quality points: 46.3. Total credit hours: 13. Divide 46.3 by 13, and your semester GPA is 3.56.
Cumulative GPA Across Semesters
Your cumulative GPA covers every graded semester, not just the current one. To calculate it, don’t average your semester GPAs together. That would give each semester equal weight regardless of how many credits you took. Instead, add up all quality points from every semester and divide by all credit hours from every semester.
For example, if you earned 46.3 quality points on 13 credits in the fall and 39.6 quality points on 12 credits in the spring, your cumulative GPA is (46.3 + 39.6) ÷ (13 + 12) = 85.9 ÷ 25 = 3.44. The result is typically rounded to two decimal places.
Weighted GPA for AP, Honors, and IB Courses
Many high schools calculate a weighted GPA that rewards you for taking harder classes. The standard approach adds 0.5 points for honors courses and 1.0 point for AP or IB courses. That creates a scale that can go above 4.0, up to 5.0.
Under this system, a B in a regular class is still 3.0, but a B in an honors class becomes 3.5, and a B in an AP or IB class becomes 4.0. An A in an AP class is worth 5.0. This means a student with a mix of AP and regular classes can have a weighted GPA above 4.0 even without straight A’s.
Not every school uses the same weighting system, so your transcript or school counselor can confirm the exact scale. Colleges reviewing your application typically recalculate GPAs on their own scale anyway, so don’t worry if your school’s method differs slightly.
Converting a Percentage to a 4.0 Scale
If your school grades on a 100-point percentage scale instead of letter grades, you can convert to a 4.0 scale. The rough ranges are: 90 to 100 corresponds to 4.0 (an A), 80 to 89 corresponds to 3.0 (a B), 70 to 79 corresponds to 2.0 (a C), and 65 to 69 corresponds to 1.0 (a D). Anything below 65 is 0.0.
For a more precise conversion, some schools use a simple formula: multiply your percentage GPA by 4.0, then divide by the total scale. On a 100-point scale, a 97 converts to (97 × 4.0) ÷ 100 = 3.88. This is especially useful when applying to colleges that require your GPA on a 4.0 scale.
How Pass/Fail and Retaken Classes Factor In
Pass/fail courses generally don’t affect your GPA when you pass. You earn the credit, but no grade points are added or subtracted from your average. If you fail, though, the impact depends on your school’s policy. Some schools count the F as zero points while still adding the course to your total credit hours, which drags your GPA down. Others exclude the failing grade from the GPA calculation entirely, though you still won’t receive credit for the course.
When you retake a class, many schools use “grade replacement,” meaning only the new grade counts toward your GPA and the original grade is excluded from the calculation (though both may still appear on your transcript). Other schools average both attempts. Check your school’s specific policy before assuming a retake will erase a bad grade.
Quick Way to Estimate Your GPA
If you just want a ballpark number without pulling out a calculator, think of your grades as a mix. Mostly A’s with a few B’s will land you somewhere around 3.5 to 3.7. A roughly even split of A’s and B’s puts you near 3.5. Mostly B’s with a couple of C’s will be around 2.7 to 2.9. One F in an otherwise solid transcript can drop your GPA by 0.3 to 0.5 points depending on how many total classes you’ve taken, because the zero pulls the average down significantly.
For precision, your school’s registrar or online student portal almost always displays your official GPA, updated each semester. That number is what employers and graduate programs will see, so it’s worth checking that it matches your own calculation.