P = bust circumference
Your measuring tape should be horizontal as it goes around the fullest part of your chest. Don't hold your breath while taking the measurement.
T = waist circumference
This is your abdominal measurement. Keep the tape horizontal as it goes around your waist at its narrowest point.
B = hip circumference
Wrap the tape horizontally around the widest part of your hips and buttocks.
E = inseam length
Measure the height from your inner thigh to your ankle.