How to calculate your whole highschool gpa

Okay so I started off freshmen and sophmore year gpa wise not so great with a 3.10 (average of both years. weighted/unweighted. I Feel like i just started to apply myself junior year. I have almost all A’s (final average) so my Gpa is a 3.75 unweighted for my junior year if i keep it up. Ive been trying to calculate my final gpa for all 3 years through gpa calculator.net but i do not know how accurate it is. Could anyone help? My final average grades for this year are
Honors physics: 93
Honors chemistry: 90
Advanced algebra: 86
Honors US History: 94
Spanish 2: 90
Marketing: 97
American Lit: 86

Freshmen and sophmore gpa averaged is a : 3.10
Could you help me find my average gpa of all 3 years? Weighted and unweighted.

Also if I get about a 30 on the ACT. What are my chances to get acepted into The University of Alabama with my current gpa? And do they take senior grades into account?

Your cumulative GPA, as calculated by your high school, should be listed on your transcript.