GPA calculator
A student with straight Bs (3.0 GPA) who takes one more class and gets an A raises their GPA to only 3.17. But if they had 40 credits of Bs and get an A in a 4-credit class, they reach 3.09. GPA is weighted by credits, so the more credits you have, the harder it is to move your GPA in either direction. Early grades matter disproportionately.
Good to know
Weighted vs. unweighted GPA. Some high schools weight honors and AP classes (5.0 for an A instead of 4.0). A student with a 4.5 weighted GPA took harder classes, not necessarily performed better. Colleges typically recalculate GPAs using their own standards. For college students, unweighted is standard.
Credit hours magnify impact. A 4-credit class affects your GPA four times as much as a 1-credit class. A C in a 4-credit core class hurts more than an A in a 1-credit elective helps. When choosing classes strategically, consider credit weights.
GPA is path-dependent. Two students with identical final GPAs had different trajectories. One might have improved from 2.5 to 3.5; another declined from 3.5 to 3.0 then recovered. Transcripts show this story; GPA alone doesn't. Admissions officers read transcripts, not just GPAs.
Disclaimers & sources
For reference only. Grading policies vary by school.