How credit-weighted GPA actually works
Grade Point Average converts letter grades into a single numerical summary of academic performance, but a simple average of grades would treat every course equally regardless of its size. Credit-weighting fixes this by giving larger courses proportionally more influence on the final number.
GPA = Σ(grade points × credit hours) ÷ Σ(credit hours)
In practice, this means a 4-credit course contributes four times as much to your GPA as a 1-credit course with the same letter grade — which matches how most universities actually calculate the figure that appears on an official transcript.
Grade scales vary by institution
This calculator uses the standard US 4.0 scale with plus/minus increments (A = 4.0, A− = 3.7, B+ = 3.3, and so on), the most common convention. Some schools use a flat scale without plus/minus distinctions, and some use scales that go above 4.0 for honors or AP courses — if your institution differs, the underlying credit-weighting principle still applies even if the specific grade-point values need adjusting.
Why one bad semester rarely sinks a GPA
Because cumulative GPA averages across every credit hour ever taken, a single difficult semester has a diminishing effect on the overall number as more credits accumulate over time — which is part of why academic advisors often emphasize that an early rough patch is more recoverable than it might feel in the moment.