How are overcoats sized?

[Uhu]

Hi!

Before I go looking online for a vintage trench coat, to wear over a suit jacket, it occurred to me, I need to know how coats are sized. Are overcoats sized by chest measurements alone, or do they take into account a suit jacket worn underneath? In other words, if I wear a size 40 suit jacket, and I need a coat to go over it, do I order a size 40 coat? Or a size 42?

Thanks in advance and sorry if this has been asked before-- my general search did not turn it up.

-Dave

 

[Vince in Philly]

Overcoats are sized to wear over your suit jacket, so if you wear a size 40 suit jacket you should look for a size 40 overcoat. That said, when you are looking at vintage coats you always want to check the measurements

 

[Doctor Damage]

Sizing is by suit size, plus Short/Regular/Long. If you're over 6' in height, then aim for long. I've noticed which I'm sure others here have, that true vintage from decades ago is a bit slimmer than more recent stuff. As Vince says, check measurements. But 9 times out of 10 you can just get your suit size and be okay, as long as you get length right. What's your height?