URGENT!! How do you calculate your GPA?

I'm a us citizen living abroad attending a plain public school. they never heard of a gpa in my school so I have to figure it out myself. I have my grades in letters (A+, A , A- B etc....) . so now how do I figure out my gpa from this.. I'm guessing i multiply each letter by a number between 1 and 4 but what are the exact numbers?
Thanks a lot. this is really urgent as I must get a lot of the applications out this week, its vacation here next week so no college couselor at school to do the forms.</p>

<p>It all depends on the school, but the standard is:</p>

<p>A+ 4.3
A 4.0
A- 3.7
B+ 3.3
B 3.0
B- 2.7
C+ 2.3

<p>thanks a lot enviroman for your quick answer.
problem is with that my gpa come out to 3.55 UW , 3.6 W.. By french standards (I live and go to school in france) 3.6 is great (test are graded on 20 , a 12 (=60 in america) is considered good, 14 is amazing and over 14 means you have a mental problem ;-) , best gpa in my class is probably about 3.7. more or less , french high school is extremely high level but has a very different philosophy concerning grading compared to America.</p>

<p>Does this automatically disqualify me from almost all good schools or are they aware that things are very very different here?
otherwise I have 1390 SAT , 640 WR SAT 2 , 620 World History and 800 French , top 10% of class ,which I think is not bad (and decent EC considering schoolday here is 8:30AM to 5:30 PM ) so I really dont want my GPA to disqualify me right away. Please help me!</p>

<p>do most universities also have the letter plus and minus things

<p>or do they usually just have the letter?

my school uses the plus and minus which i think is fair.</p>