How GPA is calculated
Each letter grade has a point value: A = 4.0, A− = 3.7, B+ = 3.3, B = 3.0 and so on down to F = 0. Multiply each course's points by its credits, add those up, and divide by the total credits. Courses with more credits count for more, which is why a B in a 4-credit course pulls your GPA down more than a B in a 2-credit course.
For example, an A in a 3-credit course, a B+ in a 4-credit course and a C in a 2-credit course gives (12 + 13.2 + 4) ÷ 9 = 3.24.
Scales differ between schools
Some universities give an A+ 4.3, some don't use plus and minus grades at all, and countries such as Pakistan and India often use percentage or 5- and 10-point scales. Check your institution's conversion table for official purposes.