ChestCheck the circumference starting from inside the armpit and passing through the nipple. Be careful not to twist the tape and ensure that the tape is parallel for an accurate check.
ShoulderCheck that the tip of the left shoulder blade is parallel to the tip of the right shoulder blade. However, in the case of muscular men, you will know your size better.
Sleeve LengthCheck the length from the shoulder blade point where you measured shoulder width to the wrist bone using a straight line.