Calculating GPA

Anyone have any idea on the number system med schools use to calculate overall GPA? Is it different for each, or does AMCAS have a system?
I’ve been to 2 schools to do post-bacc work, and both use different numbers for grades. For example, at one school an A- is equal to 3.67 whereas at the other it’s 3.75.
On top of that, I went to a completely different university for my undergrad degree, and another for grad school – and they each had their own scale.
Also, I also heard that grad school grades are “discounted” or counted for less (i.e. an A is worth a B, a B is a C, etc. – this is a nonscience masters I have).
I’m totally confused and hoping someone can enlighten me!!

AMCAS has the scales for all the schools and will apply the one appropriate for your school to the grades for that school - and if your scale isn't there, you can set it up so that it will match your transcript for grade points.
as far as grad school - I don't have any grad school grades so cannot speak from experience, but my belief is that AMCAS leaves them alone - matching the transcript.
now - individual medical schools might apply their own weighting formulas for grad school or for different ugrads (e.g. tough schools might get a multiplication factor to weight the GPA higher)
but AMCAS is pretty straight.

I'll just describe what I observed when I filled out my AMCAS four years ago - it wasn't online then but to the best of my knowledge, the system for computing GPA hasn't changed.
I had some B+ (and maybe some C+, I don't remember) grades from two different schools, U.Va. and Georgetown. Those two schools weighted those + grades differently - one gave a 3.5 to a B+, the other gave, hmmm I think a 3.36 to a B+. (presumably a 3.67 was A-)
What amazed me was that AMCAS knew that the scales were different at the two schools. They ended up converting my grades to whatever scale they use, and the grades, although both were B+ on my transcript, were slightly different on the AMCAS to reflect the fact that the schools saw them differently.
I also have a vague recollection that somehow AMCAS's system gave me a teeny boost in my GPA that I hadn't counted on, but don't ask me to explain that at this late date!
Basically, you just put the grades in and the Great Mind of AMCAS does the rest.

QUOTE (Mary Renard @ Feb 3 2003, 03:36 AM)
Basically, you just put the grades in and the Great Mind of AMCAS does the rest.

Great Mind of Amcas?! You obviously didn't apply the summer of 2001...he he

Thanks for your input! Last night after work, I did some digging around and I did manage to find some site that talk about the AMCAS scale, but I still couldn't find any info on grad school grades.
Here's what I managed to scrounge up about the AMCAS scale with regard to ugrad grades:
A 4
A- 3.7
B+ 3.3
B 3
B- 2.7
C+ 2.3
C 2
C- 1.7