The GPA Calculator will calculate your undergraduate GPA on the common scale that all graduate medicine schools use (from 0 to 7). Simply add all of your subjects to the list on the left and the calculation will automatically update. Note that the "target university" is not the university you attended, it is the university that you wish to calculate your GPA for. Some universities do not use the standard GEMSAS method for calculating GPAs and the GPA Calculator takes this into account. Your GPA for application to one university may not be the same as your GPA for another university.
All "years" mentioned on this page refer to full-time equivalent years. ACER suggests that those who have completed their degrees part time group their subjects into full-time equivalent blocks based on the order in which the subjects were completed. So, for example, if you completed a three-year degree over six years part-time, then you would still split your subjects into Year 1, Year 2 and Year 3 equivalent to the full-time degree. Note once again that this calculator is provided as a guide only. To confirm your exact GPA you must still contact the university you are applying to. If you have any comments, suggestions or bug reports, please post them at the bottom of the page. Answers to many common GPA-related questions can be found in the PagingDr GPA thread.
As of the 2014 admissions cycle, USyd has decided to outsource their GPA calculations to UAC. The calculation method outlined on their website is a little unclear and so until I have further information about how UAC calculate the GPA, I have disabled USyd as a 'target university' in the calculator.