How to calculate GPA? I am applying for the Masters in the US for the Spring 2019 session. I don't understand the concept of GPA. 
I have done my masters in Physics.  My doubts are as follows:
1. For my three-year undergrad degree in Physics do I need to calculate the score of the last year or all the three years (as in my country what you scored in the final year matters for admission)
2. My Master's is calculated on a 7 point scale. Like my GPA is 4.33/7. How to convert this on 4 point scale?
3. I come from a lower middle-class family and applying to the US universities will come costly to me. So I wish to email shortlisted university for my profile evaluation. Will they help out? How do I approach them?
Don't convert it. Most places I applied to only required that you submit your grades based on how your institution provided you. For your case, that would be 4.33/7. Do not manually convert the scale unless being explicitly told to do so by the university you're applying to.