Chest: Get the circumference of your chest in a natural position by using a measuring tape and keeping it parallel to the ground. The measurement needs to be done without clothes or with a thin t-shirt.
Arm Length: Stand in an upright posture and get the measurement from the shoulder blade up till the wrist bone along the outside of the arm.
Waist: Measure from above the hip bone all the way around your body and keep the tape parallel to the ground and in level with the belly button.