you can calculate your GPA yourself from the overall marks you get on Tuesday.
Marks are awarded the following points.
hd=7 d=6 c=5 p=4
To calculate your GPA you add all the points your units awarded you together and divide that by the number of subjects you did. For example if you get 1 pass, 1 credit, 1 distinction and a HD you would add 4+5+6+7, which adds up to 22, then divide 22 by 4 as that is the number of subjects you have undertaken...this would give you a GPA of 5.5.
However you will receive something in the post a few days after Tuesday with your exact marks, i.e. where within a specific grade bracket you actually fell. That is if you got a distinction, whether you got 75 or 84 etc. Your GPA will be written on the same bit of paper, but as I said you can work that out beforehand on Tuesday.