Dungaree Relaxed Size

Waist    Using a measuring tape, measure the smallest part of your waist. Not too snug, not too loose. 
SEAT    Measure around the fullest part of your hips. Make sure to keep the tape measure as horizontal as you can. 
THIGH   Measure around the fullest part of your thigh.
INSEAM    Measure straight down the inside leg from the crotch to the ankle.