How do people measure their bi-deltoid ?

[Gandy_save_us]

I've notice that people measure differently when they measure their bi-deltoid like some will measure with a tape measure and curve it round the end of the shoulders either measuring from the front or back and then some people will be against a wall and draw lines and then measure is there one good measurement cooked for knowing your deltoid width without going to the doctors and having them use that biacromial measuring stick thing
How would you lot do it ?

 

[user20266741]

Measure biacromion to find out if its over or not

 

[Gandy_save_us]

Measure biacromion to find out if its over or not

16 inchs or so at 5,10 is it over ?

 

[user20266741]

16 inchs or so at 5,10

Yea I only know whats the ideal widt when youre 6'3

 

[Gandy_save_us]

Yea I only know whats the ideal widt when youre 6'3

the one with bullet points is the 5,10 one and im just above 16 inchs so its probably just above average btw is biacromial from collar bone to collar bone ?