When finding high school GPA do you add yearly final grades and divide by 4 or all of the from highschool total number them?

You don't simply add yearly final grades and divide by 4. High school GPAs are calculated by adding up the grade points earned in *all* courses taken during high school and then dividing by the total number of courses.

Each course grade is assigned a numerical value (e.g., A = 4.0, B = 3.0, C = 2.0, etc.), and these values are summed. Then this sum is divided by the total number of courses to arrive at the GPA. The weighting of courses (e.g., honors or AP classes) may also be factored in, depending on the school's specific GPA calculation method.