How GPA is calculated
Grade point average is a weighted average. Each course's grade is converted to grade points, multiplied by the course's credit hours, and the total is divided by the total credit hours, so a four-credit course counts more than a three-credit one. For example, an A (4.0) in a 3-credit course, a B (3.0) in a 3-credit course and an A− (3.7) in a 4-credit course give a GPA of 3.58 over 10 credit hours.
Grade scales differ
Schools do not all use the same scale. The calculator starts with the common US 4.0 scale with plus and minus grades, but that is only a starting point: open the grade scale section to change any grade's point value so it matches your institution, for example if your school gives 4.3 for an A+ or does not use minus grades. Check your school's official policy for the scale it uses.
Rows that are skipped
A course row with no grade selected is ignored rather than counted as zero, so an unused row never lowers your average. A graded course needs credit hours greater than zero; if one is missing, that row is flagged and left out until you fix it.
Limitations
This calculates a simple weighted GPA from the courses you enter. It does not apply institution-specific rules such as repeated-course replacement, pass/fail courses or weighting for honors classes, so your official GPA may differ.