How weighted GPA is calculated
Weighted GPA multiplies each course's grade-point value by its credit hours, sums those products, then divides by total credit hours. A 4-credit course with an A (4.0) contributes 16 grade points; a 3-credit course with a B (3.0) contributes 9. Total: 25 grade points across 7 credits = 3.57 GPA.
This matches the standard formula used by every US university registrar and most international institutions that have adopted the 4.0 scale.
US, UK, and percentage scales, which to use
Use the US 4.0 letter scale if your transcript shows letter grades (A+, A, A-, etc.). Use the UK percentage mode if you receive a final mark out of 100, this tool will additionally show your degree classification (First, 2:1, 2:2, Third). The generic percentage mode is for any system that grades in percentages without UK class boundaries.
If your university uses a 5.0 scale, a 7-point scale, or competency-based grading (like WGU), use the percentage mode and convert manually using your school's published conversion table.