The formula
GPA = sum of (points × credits) ÷ total credits
Where it comes from
GPA is a weighted average where the weight is the credits of each course. Each grade is converted first to the 4-point scale — an A is 4, a B is 3 — and multiplied by its credits to give the quality points. The sum of those points divided by the total credits is the GPA.
How to work it out by hand
- Convert each grade to points: A is 4, B is 3, C is 2, D is 1 and F is 0
- Multiply each course's points by its credits
- Add all those products: those are the quality points
- Divide by the total credits taken
What is worth knowing
The credits are what stop GPA being an ordinary average. An A in a 4-credit course and a C in a 1-credit one does not give 3, it gives 3.6, because the good one weighs four times as much. It works the other way too: failing a course worth many credits sinks the transcript far more than the number of courses suggests. The signs move the mark a third of a point — a B+ is 3.3 and a B− is 2.7 — though not every university uses them. And while the conversion to a 10 or 100 scale is approximate, it is the one most international applications accept.