S  M L
PTP 15.5 -16" 16.5 -17" 17.5 -18"
Waist  13" 14" 15"
Length 16" 16.5" 17"

*Model is 1.68m, UK 6 (PTP15.5", Waist 12.5") and wears size S.

If you are in between size for PTP/Waist, it is best recommended to size up.

*In between sizes refers to your measurements falling between 2 sizes, example size S & M.