Need help on GPA calculation

<p>I’m studying at very competitive private school in Canada.
All courses are taughted at honours level except 3 AP courses like chemistry, Physics and Math. Our school doesn’t have GPA or ranking system so I want to do it myself.
From Grade 9 to Grade 11 now, I have all A and A+ so my GPA will be 4.0/4.0
if it is unweighted ?</p>

<p>Pls advise whether it is right or not.</p>

<p>Our Grading is as folow.</p>

<p>Scale:0 ~ 100, Honours:80 ~ 100, Pass:50</p>

<p>90 ~ 100:A+, 80 ~ 89:A, 70 ~ 79:B, 60 ~ 69:C, 50 ~ 59:D, below 50:F</p>