how do duffle coats typically fit?

[fearbecomesfact]

i'm buying a duffle coat online, and i'm curious to know how they typically fit. whenever i've tried on a pea coat or similar styles, they aren't snug, but almost. are duffle coats meant to be worn a little more loose? i usually wear an XL size jacket for shoulder width and arm length, so i was thinking of getting an XXL.

 

[Master Squirrel]

Depends on the brand and if you are wearing a jacket underneath.

 

[fearbecomesfact]

it's BGSD. i don't plan on wearing a jacket underneath. maybe a cardigan sometimes. i want it to be somewhat roomy, but i don't want to be swimming inside of it.