S   M   L
Bust 15.5-16" 16.5-17" 17.5-18"
Waist 16" 17" 18"
Length 20" 20.5" 21"

*Model is 1.70m, UK4/6 (PTP 15", Waist 11.5") and wears size S

There's allowance at the chest and waist. You may stick to your usual size for a relaxed fit or size down for a slimmer fit.