Venom, it does go over the shoulder a bit. Aim for getting it slightly wider than your armpits.
The piece actually tapers outwards so the lower arm opening is actually the widest part.
If you put your arms to your sides, and get someone to measure across the widest part of your shoulders, that
should be as close to the scale you'd use. Remember the Shoulder bells cover up a lot so you can customise it.
The suit is very short, but once the belt is added, then later the hoses or whatever to link
up the belt to the chest, you'll find it's not too bad.