Originally Posted by Peacoat
Joonian is right; it should cover the butt, and not much more than that. You will find that some designers make their pea coats shorter, or longer, depending on their whim of the moment. But those aren't really pea coats--they are peacoat inspired fashion garments.
Peacoats are designed for men who have started to fill out, who have put on some weight from their adolescent years and who have developed some muscle. They aren't designed for someone who is 5'11" and 145 lbs. with no body fat and little muscle.
For my height, I am perfectly proportioned, In other words the peacoat model is based on someone with my measurements, so it is easy for me to find a peacoat that fits well. To give an example of fit, my chest measures 42". A size 42 vintage Navy peacoat is a good fit for me and allows room for a sweater underneath. It isn't a tight fit, but it is a practical fit. If I don't need a sweater on a particular day--say the temps are in the low 40s--I can wear a size 40 peacoat. There is no room for a sweater, but the fit is slim. Still comfortable but slim. The size 40 fits closer to the body and is warmer without a sweater than the 42.
I mention the stated tag size of the pea coats, but the most important number is the actual measured pit to pit size. Most, or perhaps all, of my size 42 pea coats measure right at 22.25". My size 40 peacoat measures 21.25". These are the standard measurements in those sizes for vintage (pre 1980) Navy pea coats. While perhaps 90% of the coats have the same p2p for these tag sizes, some are a bit larger. That is why I stress the importance of first measuring the circumference of one's chest and then getting an accurate p2p measurement from the seller. While usually an accurate guide, the stated tag size can be different from the actual size of the peacoat. Doesn't happen often, but it does happen.
So, if one wants a slim fit with a 42" chest, the size 40 peacoat would be the one to look for (in the vintage models). For a chest of 40" the size 38 would be the way to go. Assuming, of course, that the p2p is 20.25". For the smaller sizes, the p2p measurements are not what I would expect to see. I have three size 34 pea coats, each with a p2p of 19". We would expect these coats to have a tag size of 36, and to fit like a small size 36. I have also received numerous measurements from others with size 34 pea coats. Most of these also have a p2p of 19", although I have seen a few of a little over 18". So, when we get down into the smaller sizes, I'm not sure about an accurate guide to fit.
The WWII peacoats (8 buttons showing) will fit a little tighter than the vintage models (post war 1945--1946 to 1979), and the current issue (1980 through current) will be a little larger, in general, than the vintage models. For a slim fit in a WWII model, probably not a good idea to buy a peacoat a size smaller than one's measured chest size.
For sleeve length, I like the peacoat to strike at least an inch below the wrist joint. If it is longer than 1/2 way from the wrist to the web of the thumb, it is a bit too long.
These chest sizing guides are based on the US Navy pea coats only. I have no idea how makers of the fashion garments size their coats, but I imagine the p2p guide would still be valid. The body length and the sleeve length should be applicable to the fashion garments as well. The key is getting the seller to give an accurate
p2p measurement. Also, in my opinion if one still has the body of an adolescent--no body fat and little muscle mass--It would be better to pursue a fashion peacoat, rather than the Navy peacoat.