which one are you interested in? If you look at the customer reviews for the item then people usually mention sizing/fit etc. Alternatively, link on here to the ones you like and I am sure one of us on MN will own it already
IME, Boden coats come up small. I am a size 8 in everything from Boden except for coats when I usually have to size up.
I have the biker jacket in brown from this years' catalogue. It is fab - very warm and stylish. Far better looking IRL than on the weird angled photo! I sized up based on other people's reviews which means I can now fit chunkier knitwear beneath too.
I'd say coats come up small- I wear a size 8 -10 normally in Boden tops/cardis and a 10 in trousers and skirts. I have got the uptown coat (boiled wool) and have a 10 - that's a good fit, but the sleeves are long- but that's just me- I have short arms.
If you are between sizes, I'd go up especially as you will be wearing a jumper etc underneath.
I got it with 20% off so it wasn't too expensive.
TBH I don't think you can get a decent coat for under £100 if it's mainly wool.
I have a crombie type coat from NEXT that is 70-80% wool and it's now in its 4th year, although don't wear it much as it's formal, and another coat from JL that is on its last legs coming up for the 4th season. The JL coat ( from the YOUNG FASHIONS) dept is not all wool, it's a tweedy mix, and it did bobble quickly.