How do I calculate my GPA?

I’ve found out that the standard GPA scale is a little like this: http://www.collegeboard.com/html/academicTracker-howtoconvert.html
However, my scale uses a very different scale. For example, an 80 is a 2.7 on that scale but at my school it is a 2.0. So, my GPA isn’t exactly where I’d like it to be, but on that scale it’s much higher.
My question:

  1. I’ve heard colleges recalculate GPA using their own system. Is this true? Is this scale tougher?
  2. Will they see the GPA my school records on my transcript? Or will they recalculate it?
  3. Looking at my GPA, should I calculate it the standard way or my school’s way (when applying to programs, etc)?

And yes, I’m striving for the highest possible GPA in both scales.

My third time posting on CC, really glad I found this site it has a plethora of advice, thanks in advance,

1 - many do
2 - yes and maybe
3 - Use your school’s info.

Ask your GC how to convert it into the tradition 4.0 scale if some of your forms are requesting that. You’re certainly not the first to cross that situation