Pajama Size Chart Men's. To get your sizing right for your pyjamas, measure the best all around at the fullest part. Next you need to find out your sleeve length, measure from the centre point of your shoulder down to your wrist.

These two measurements will help you decide your nightshirt size. Remember to place the tape measure under your arms. Next you need to find out your sleeve length, measure from the centre point of your shoulder down to your wrist.