As shoulder width is measured along the upper portion of the back, you will need the help of another person to measure this.
With the back straight, measure from tip of one shoulder to the tip of the other shoulder.
This is the thickest part of the arm, which is usually the midpoint between the tip of your shoulder and the tip of your elbow.
Stand straight with your arms relaxed at your sides, take the help of someone else to measure the arm width/biceps around the midpoint of the arm as described above.
With the back straight, measure around your chest, just under the arms and just above the bust.
With the back straight, wrap the tape around your chest, just under the bust, keeping tape parallel to the floor.
It is the place where you wear your jeans/trousers. It is below the natural waist and is the widest part of the waist just above the hip bone, keeping tape parallel to the floor.
Stand straight. Wrap the tape around the thigh and measure the circumference of the fullest part of the thigh.