Semester and Cumulative GPA Calculator:

This calculator will compute your GPA for a single semester or, if you know your current GPA and total number of credits, it will compute your cumulative GPA including these current grades.  It should be self-explanatory and you can use either upper- or lower-case letters for the grades.  It will also compute your new GPA after a semester's grades, providing you know your current GPA and the number of credits you've taken.

Credit for the above calculator goes to Matt Stueve

Target GPA Calculator

This calculator will tell you what GPA you will need for your next semester, year, etc. to reach a GPA goal. You just need to know your current GPA and the number of credits you've already completed. Then choose a target GPA and a number of credits in which to attain that target!

Course-Repeat GPA Calculator

This calculator will allow you to compute the effect of retaking a course with the new grade replacing the original one.
Note: If you retake a course, do not list that course in the Cumulative GPA Calculator — that calculator will just add it as if it is a new course.

To find your actual new GPA, use the Cumulative GPA Calculator inputting the non-repeated courses and then use this one to see the effect of the repeated course. Here you need to know your current GPA and the number of credits you've completed, and, of course, the number of credits and the two grades (as always, you can input either upper- or lower-case grades) for the course in question.