Size Waist Hip Inseam AU/UK/NZ US
XS 61-65 81-85 61 4-6 2-4
S 66-70 86-90 62 8 6
M 71-75 91-95 62 10 8
L 76-80 96-100 63 12 10
XL 81-85 101-105 64 14 12

All measurements are in cm.
Olga is 178cm, AU 8; wears size Small.