GPA Calculator (4.0 / 4.3 / 4.5 scales)

GPA is a credit-weighted average: Σ(grade × credits) / Σ(credits). Different schools use different scales — US standard is 4.0 with A=4.0; A- = 3.7, etc. Some US schools award A+ = 4.3 (Cornell, Stanford). Korean universities typically use 4.5 (A+ = 4.5, A = 4.0, B+ = 3.5, …). This tool handles all three, supports an unlimited number of courses with editable name/grade/credits, and shows GPA, total credits, and total quality points.

Weighting by credits is the whole of the calculation and the part most people skip. A straight average of letter grades treats a one-credit seminar the same as a four-credit core course, which can move the result by several tenths in either direction. If your figure disagrees with the registrar's, the weighting is the first thing to check and usually the answer.

The scales are not convertible by arithmetic. A Korean 4.5 GPA is not a US 4.0 multiplied by 0.888, because the two systems differ in where the grade boundaries sit and in how the letters map to points, not merely in the top number. Institutions that accept foreign transcripts run them through a published conversion table or a credential evaluator, and a ratio calculated at home will not match what they use.

What counts toward the average is a policy question rather than a mathematical one. Pass or fail courses, withdrawals, transferred credits, repeated courses where one attempt replaces the other, and courses outside the major each have institution-specific treatment. A calculator can only average what you enter, so the figure it gives is as correct as your understanding of which rows belong in it.

The quality points total is the number worth watching if you are trying to move a GPA. It makes plain how much inertia a transcript has: after a hundred credits, a single semester of straight A's shifts the cumulative figure by a fraction of a point, and no arrangement of future grades recovers a bad year quickly.