This is an approximate conversion table to help you find your size.
How to get your best size:
Chest measurement: Grab a tape measure and wrap it underneath your armpits at the fullest part of your chest. Keep the tape measure levelled at the front and the back of the body. The tape measure should be taut but not squeezing hard against the skin.
Waist measurement: Measure the smallest part of the waist. Make sure it's not too tight and that it's straight, even at the back. Don't hold your breath while measuring.
Hip measurement: Measure the largest point of the hips. Make sure it is straight the whole way around.