I'm an American whose lived in both the UK and now in France - clothes sizes are a bit baffling, but if Australia uses UK or Asian sizes it goes like this:
Women's Clothing Sizes
UK 8 10 12 14 16
USA 6 8 10 12 14
Continental 36 38 40 42 44
Japanese 7 9 11 13 15
Bust 32" 34" 36" 38" 40"
Waist 24" 26" 28" 30" 32"
61cm 66cm 71cm 76cm 81cm
Hip 35" 37" 39" 41" 43"
89cm 94cm 99cm 104cm 109cm
Some styles are sized small, medium and large. The chart below shows explains the sizes.
Order Size S8/10 M12/14 L14/16
Bust 32"-34" 34"-37" 37"-40"
cm 81-86.5 86.5-94 94-101.5
Hips 33"-36" 36"-39½" 39½"-42"
cm 84-91.5 91.5-100.5"
100.5-107
I got this chart from :
http://www.ethicallyme.com/help_sizes.html
Hope that helps