The U.S. high school and college grade point scale spans from 4.0 to 0.0. Every letter grade has a point equivalent. The purpose of the numeric scale is to enable a mathematical calculation of a student's overall performance in his or her classes; this would not be possible using only letters. The resulting average is a student's overall GPA which allows comparison and ranking of students' work to one and other.
In high school, two different scales are typically used. The 4.0 scale is used for regular classes. If a student takes advanced classes like honors, AP (Advanced Placement) or IB (International Baccalaureate), additional points are added for each grade to recognize the rigor of these classes.
This is the standard conversion used between letter grades and GPA
| Grade | Points |
|---|---|
| A+ | 4.0 |
| 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 |
The weighted scale adds a half or whole point onto each grade taken in an advanced class.
| Grade | Honors Points | AP/IB Points |
|---|---|---|
| A+ | 4.5 | 5.0 |
| A | 4.5 | 5.0 |
| A- | 4.2 | 4.7 |
| B+ | 3.8 | 4.3 |
| B | 3.5 | 4.0 |
| B- | 3.2 | 3.7 |
| C+ | 2.8 | 3.3 |
| C | 2.5 | 3.0 |
| C- | 2.2 | 2.7 |
| D+ | 1.8 | 2.3 |
| D | 1.5 | 2.0 |
| D- | 1.2 | 1.7 |
| F | 0.5 | 1.0 |
Using the traditional academic performance definitions for letter grades, the GPA scale can be broken down as follows. The average GPA in high school is a 3.0, so anything higher than that is a good GPA.
You will almost always find your GPA already calculated and printed on your report card. If you're curious how it's calculated or if you need to calculate it on your own, here is how to do it. Calculation starts with the overall letter grades given to you by your teacher in each class. Every letter grade from A+ to F has a grade point value assigned to it.
In high school when using the unweighted 4.0 scale, the calculation is then pretty straight forward. Take every grade point you've earned and add them up. For example
3.3 + 4.0 + 3.7 + 3.0 + 3.7 = 17.7
Now divide the results by total number of classes
17.7 ÷ 5 = 3.54 GPA
To calculate a weighted GPA we must determine if a a class' grades are awarded extra grade points and factor this in. AP and IB courses are given an extra whole grade point and honors classes are given an extra 0.5 points. If the 4.0 (A) in the above example was earned in an AP class, that A would be worth 5.0 points instead if 4.0. The GPA calculation would look like this.
3.3 + 5.0 + 3.7 + 3.0 + 3.7 = 18.7
Now divide the results by total number of classes
18.7 ÷ 5 = 3.74 weighted GPA
For college, we have to consider the number of credit hours each class is worth (usually 3 or 4) and multiply each class' grade by credits. For example
(3.3 × 3) + (4.0 × 3) + (3.7 × 4) + (3.0 × 3) + (3.7 × 3) = 56.8
Now divide the results by total number of credits
56.8 ÷ 16 = 3.55 GPA
Conversion table of the unweighted 4.0 grade point scale with letter grade and percentage equivalents. This unweighted GPA scale is used my most U.S. high schools and colleges.
| GPA | Grade | Percent |
|---|---|---|
| 4.0 | A/A+ | 93-100 |
| 3.9 | A- | 92 |
| 3.8 | A- | 91 |
| 3.7 | A- | 90 |
| 3.6 | B+ | 89 |
| 3.5 | B+ | 88 |
| 3.4 | B+ | 87 |
| 3.3 | B+ | 87 |
| 3.2 | B | 86 |
| 3.1 | B | 85 |
| 3.0 | B | 83 |
| 2.9 | B- | 82 |
| 2.8 | B- | 81 |
| 2.7 | B- | 80 |
| 2.6 | C+ | 79 |
| 2.5 | C+ | 78 |
| 2.4 | C+ | 77 |
| 2.3 | C+ | 77 |
| 2.2 | C | 76 |
| 2.1 | C | 75 |
| 2.0 | C | 73 |
| 1.9 | C- | 72 |
| 1.8 | C- | 71 |
| 1.7 | C- | 70 |
| 1.6 | D+ | 69 |
| 1.5 | D+ | 68 |
| 1.4 | D+ | 67 |
| 1.3 | D+ | 67 |
| 1.2 | D | 66 |
| 1.1 | D | 65 |
| 1.0 | D | 63 |
| 0.9 | D- | 62 |
| 0.8 | D- | 61 |
| 0.7 | D- | 60 |
| 0.6 | F | 59 |