Grade Point Average (GPA), Explained
How to calculate GPA from letter grades and credit hours, the 4.0 GPA scale with plus and minus values, weighted vs unweighted GPA, and cumulative GPA.
By Udit Agarwal · Updated October 17, 2026
Your grade point average (GPA) is the credit-weighted average of your course grades: multiply each course's grade points by its credit hours, add the results, and divide by the total number of credit hours. On the common US 4.0 scale an A is worth 4.0, a B 3.0, a C 2.0, a D 1.0 and an F 0, with plus and minus grades in between. An A and a B in two 3-credit courses work out to a GPA of 3.50.
GPA = sum of (grade points × credit hours) ÷ sum of credit hours
Grade points times credit hours are called quality points. A 3-credit course with a B (3.0) earns 9.0 quality points, and a 4-credit course with an A (4.0) earns 16.0. Add up the quality points for every course, divide by the credits, and you have the GPA.
The credits matter. Take a 3-credit A and a 1-credit C: the GPA is (4.0 × 3 + 2.0 × 1) ÷ 4 = 14 ÷ 4 = 3.50, because the A covers three-quarters of the credits. A plain average of the two grades would give 3.00 and understate it. A course that carries more credits moves your GPA more, in both directions.
This is the common US scale for letter grades, and the exact values the ArrayKit GPA Calculator uses:
| Letter | Plus (+) | Plain | Minus (−) |
|---|---|---|---|
| A | 4.0 | 4.0 | 3.7 |
| B | 3.3 | 3.0 | 2.7 |
| C | 2.3 | 2.0 | 1.7 |
| D | 1.3 | 1.0 | 0.7 |
| F | n/a | 0.0 | n/a |
A plus adds 0.3 to the plain letter and a minus takes 0.3 away, with one exception: an A+ is capped at 4.0, the same as an A.
Schools set their own scales, so check yours. Some give an A+ 4.3, some use thirds such as 3.67 for an A− and 3.33 for a B+, and some do not use plus and minus grades at all. The percentage that earns each letter varies as well. A common US pattern is 90 and above for an A, 80 to 89 for a B, 70 to 79 for a C and 60 to 69 for a D, with the plus and minus cut-offs inside each band, but many schools draw the lines elsewhere. To turn assignment scores into a course percentage first, use the Grade Calculator, or the Percentage Calculator for a single test.
| Course | Grade | Credits | Grade points | Quality points |
|---|---|---|---|---|
| English | A− | 3 | 3.7 | 11.1 |
| Chemistry with lab | B+ | 4 | 3.3 | 13.2 |
| History | A | 3 | 4.0 | 12.0 |
| Studio art | C | 2 | 2.0 | 4.0 |
| Total | 12 | 40.3 |
GPA = 40.3 ÷ 12 = 3.358, which rounds to 3.36. A plain average of the four grade points, (3.7 + 3.3 + 4.0 + 2.0) ÷ 4, would give 3.25. The credit-weighted figure is higher because the C is in the smallest course.
Your cumulative GPA covers every term so far. Work it out the same way, with total quality points divided by total credits. Averaging the semester GPAs gives the wrong answer whenever the semesters carry different numbers of credits.
Suppose the fall term had 15 credits at a 3.20 GPA and the spring term 12 credits at 3.75:
Averaging the two GPAs would give 3.475, which is too high because the stronger term had fewer credits. When you rebuild quality points from a transcript, use the credits that count toward the GPA, often labelled GPA hours or quality hours. They can be lower than the credits earned if some courses were graded pass/fail.
The same arithmetic shows why a cumulative GPA moves slowly. A student with a 3.00 over 60 credits who then earns straight A's across 15 credits reaches (3.00 × 60 + 4.0 × 15) ÷ 75 = 240 ÷ 75 = 3.20. The more credits behind you, the more each new term is diluted.
An unweighted GPA puts every course on the same 4.0 scale, so 4.0 is the maximum. A weighted GPA, common in US high schools, gives extra points for harder courses such as honors, Advanced Placement (AP) or International Baccalaureate (IB), so it can go above 4.0. A common convention adds 0.5 for honors and 1.0 for AP or IB courses, but schools differ, and many colleges recalculate applicants' GPAs with their own rules.
Here is the same five-course schedule both ways, using the 1.0 bonus that the ArrayKit calculator applies to every course you mark:
| Course | Grade | Unweighted | Weighted |
|---|---|---|---|
| AP Calculus | B | 3.0 | 4.0 |
| Honors English | A− | 3.7 | 4.7 |
| Biology | A | 4.0 | 4.0 |
| History | B+ | 3.3 | 3.3 |
| Spanish | A | 4.0 | 4.0 |
| GPA (1 credit each) | 3.60 | 4.00 |
The B in AP Calculus counts the same as the A in Biology once it is weighted, which is the point of weighting: it rewards taking the harder course.
The GPA Calculator gives you a row per course: choose the letter grade from A+ to F, enter the credit hours (half credits work), and add or remove rows as needed. Switch on Weighted (honors/AP) to show an Honors/AP switch on each row; a marked course gets 1.0 extra grade point, except an F, which stays at 0. The result shows the GPA to two decimal places, the total credits and the total quality points, with a button to copy the summary. Rows with 0 or blank credits are skipped, so they cannot drag the average down.
It uses the fixed scale in the table above, so it cannot apply a 4.3 A+, a 0.5 honors bonus or a school's own scale. It also has no box for a previous GPA: for a cumulative figure, enter every course from every term as its own row. Everything is calculated in your browser, and the grades you enter are not sent anywhere.
How do I calculate my GPA? Multiply each course's grade points by its credit hours, add those quality points together, and divide by your total credit hours. For an A and a B in two 3-credit courses, that is (12 + 9) ÷ 6 = 3.50.
What is the GPA scale? In the US, most schools use a 4.0 scale: A = 4.0, B = 3.0, C = 2.0, D = 1.0 and F = 0. A plus usually adds 0.3 and a minus takes 0.3 away, so a B+ is 3.3 and an A− is 3.7, though some schools use slightly different values.
What is the difference between weighted and unweighted GPA? An unweighted GPA scores every course on the same 4.0 scale. A weighted GPA adds bonus points for honors, AP or IB courses, often 0.5 or 1.0, so it can exceed 4.0.
How do I calculate cumulative GPA? Add the quality points from every term and divide by the total credits from every term. Averaging semester GPAs only works when each semester has the same number of credits.
Can a GPA be higher than 4.0? An unweighted GPA cannot, because 4.0 is the top grade. A weighted GPA can: with a 1.0 bonus, an A in an AP course counts as 5.0, so a schedule with several weighted courses can average above 4.0.
Do pass/fail classes count toward GPA? Usually not. A pass earns credit but no grade points, so it leaves the GPA unchanged. Some schools do count a failing grade in a pass/fail course, so check your school's policy.
How much can one semester raise my GPA? It depends on how many credits you already have. With a 3.00 over 60 credits, a perfect 15-credit term lifts it to 3.20; with a 3.00 over 15 credits, the same term would lift it to 3.50.
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