Retaking a course can help or barely move the needle depending entirely on how your school counts the second attempt. This calculator models the four common policies so you can see the real GPA effect before you decide to repeat.
How it works
Your GPA is total grade points divided by total credits. The tool starts from your current totals, removes the original course’s contribution, then adds it back according to the chosen policy:
4.0 scale: A 4.0, A- 3.7, B+ 3.3, B 3.0, B- 2.7, C+ 2.3,
C 2.0, C- 1.7, D+ 1.3, D 1.0, F 0.0
replace : course counts retake grade only
average : course counts (original + retake) / 2
highest : course counts max(original, retake)
both : course appears twice; both grades counted over doubled credits
The new overall GPA is then the rebuilt grade-point total over the adjusted credit total.
Example
A 3.20 GPA over 60 credits, retaking a 3-credit C (2.0) for an expected A (4.0): under replacement the course jumps to 4.0 and the GPA rises noticeably; under average it only counts as 3.0; under both-counted the extra 3 credits dilute the gain.
Notes
Letter-to-point mappings vary slightly by school, and some cap how many courses qualify for forgiveness. Confirm your registrar’s exact scale and limits.