Check out
http://www.sro.vic.gov.au/sro/SROnav.nsf/LinkView/DA6A217C7F452EF8CA2575D20021EBE7C580F3A333F4AD44CA2575D10080AD1C
And the calculator is here
http://www.sro.vic.gov.au/SRO/SROCalcs.nsf/landtax?OpenForm
And it's only calculated on the LAND VALUE, not the PORTFOLIO value. PPOR is exempt.