I am a little confused about how I should go about calculating my major GPA. I study at the Indian Institute of Technology and as part of my curriculum, have also done compulsory(as opposed to elective) courses from other departments like Electronics, Material Sciences, Mathematics etc, apart from my courses in the humanities. I'm not sure if I should include these courses in computing my major GPA. What about my basic first year courses in physics and mathematics?

For example, I have done the following courses:

Introduction to electronics - Dept. of Electrical Engg.

Physics of Materials - Dept. of Metallurgy

Integral Transforms - Dept. of Mathematics

Mathematics I - Dept. of Mathematics

Are there any rules or guidelines regarding which courses I should include? My GPA seems to shift by ~ 0.2 depending on which way I calculate it