Just looked at my suit, I'm 5'7" & 80 KG and my suit has a label marked "M". Fitted me nicely when I was 10Kg lighter and still does. The legs are perhaps a tad long but that's no problem. It's around 8 years old so I don't know how that relates to todays models. If that's any guide then I presume M for medium would be right for you Petra (unless they make mens and ladies sizes)............. but please don't blame me if that's the wrong size.....
