Measure around the base of your neck. here the collar sits.
Place the tape measure under your arms, across your shoulder blades and around the fullest part of your chest. Remember to breath out first.
Measure around your natural waistline, keeping the tape measure taut.
Stand straight with your legs closed together. Measure the inside length of your leg from the inner top of your leg (crotch) to the floor without wearing shoes or to the point where the trouser is worn on the shoe.