A coat is the only garment routinely bought in one condition and worn in another. You try it on over a shirt in a warm shop and wear it over knitwear in February.

That single fact drives everything below.

Try it on over what you will wear

The most useful thing on this page. Wear or carry a jumper of the weight you actually own, and try the coat over it.

A coat that fits perfectly over a t-shirt will pull across the back and restrict the arms over a chunky knit, and you will stop wearing it. This is the commonest reason a coat sits unused.

The shoulder — one size up from a jacket

The shoulder seam should sit at or slightly beyond your shoulder point, which is different from a blazer.

That small extra allowance is deliberate: it makes room for layers underneath. A coat cut tight to the shoulder has nowhere to put a jumper.

As with a blazer, this is the measurement that cannot be altered affordably. Everything else can.

The back — cross your arms

Do the coat up and reach both arms forward as if driving or hugging someone.

There should be some pull, and it should release when you relax. If the back seams strain or the armhole bites, it is too narrow across the back. If you can cross your arms with no resistance at all, it is probably too big.

The armhole and sleeve

The armhole should be lower and roomier than on a jacket, again for layers.

Sleeve length is different from a blazer too: a coat sleeve should reach the base of your thumb, covering the jacket or jumper sleeve beneath. It is one of the few places where longer is correct.

Length

Largely a style decision, with two practical notes.

Anything you will sit in — a car, a train, an office chair — is more comfortable at or above the knee. A full-length coat is warmer and gets sat on.

The one length to be careful with is mid-calf, because it lands where the leg is widest and it can shorten the wearer noticeably. Dressing for your proportions covers hem placement.

Fastening

Do it up and check the front does not strain at the button or gape at the top. Then check it still hangs cleanly when open, which is how most coats are actually worn.

A coat that only looks right buttoned is a coat you will wear buttoned.

What to check on the label

Coats are where fibre content shows most, because the fabric is doing structural work.

  • Wool above 50% hangs and insulates properly, and it is the difference between a coat that looks expensive and one that does not
  • Some polyester or nylon adds durability and water resistance, and is not a compromise in outerwear
  • Mostly synthetic will be lighter, less warm, and will show its price

Is polyester always bad covers why synthetic content is genuinely correct in outerwear, and reading a composition label covers the rest.

Colour

A coat is the largest single block of colour you wear, and it goes over everything else, so it is worth taking from your own palette rather than from what is in the shops.

What goes with a camel coat covers the most useful neutral in detail, and the free colour quiz will tell you which version of it suits you.