So I just put my trial marks into two ATAR calculators - one from atarcalculator.com.au, and for the other I used SAM here on bored of studies.
My dilemma is that I put exactly the same marks into each:
Adv English 91%
Ext English 92%
Religion 2U 89%
PDHPE 85%
Legal Studies 83%
Mathematics 53%...