I normally wear AUS 10 and ordered Small for the jacket. It was a bit tight around chest area however, sleeves length and waist line were all fine. It's extremely well made, very soft fleece lined inside around neck and back of the jacket. Sleeves were long enough (My arms are very long). I'd love to keep it but once I fully zipped the jacket I couldn't move my arms properly because my chest area was too tight ( I am quite slim and wear a bra A cup) I wouldn't recommend Small to any girls out there with slim body but tall, they should go for Medium size as Small size might be more suitable for petit girls height under 163cm under 50kg.