What Size Coat Should I Buy? The Adam & Westcott Size Run
Most men order a coat the way they order a shirt, and that is where the layering goes wrong.
Last updated: September 2026
Buy your usual shirt size in an Adam & Westcott coat if it goes over a shirt, and one letter up if a sweater goes underneath. All 18 coats carry M, L, XL and 2XL, so that step up is always there. Above and below that band the range thins fast, and that is what decides which coat you can buy in your size.
In this article
- What size coat should I buy?
- Which sizes are stocked
- Sizing up over a sweater
- 3XL and above
- XXS, XS and S
- Sizing questions
What size coat should I buy?
Order your usual shirt size for wear over a shirt, one letter larger for wear over a sweater. All 18 Adam & Westcott coats stock M through 2XL, so sizing up a step is always possible.
Coats are cut with layering room built in, so your shirt size is the starting point. For what a letter buys you, the hard figure comes from the tops that publish a chart: across Adam & Westcott's 57 shirt charts each step adds 1.6 inches in the chest. A sweater takes about that much, so one letter covers it and two leaves the coat loose. Runs here are five to ten sizes, from the Explorer Rain Coat at S to 2XL up to the Long Puffer Coat at XS to 6XL.
Which coat sizes does Adam & Westcott stock?
M, L, XL and 2XL are on all 18 coats, S on 15, XS on 10, 3XL on 10, 4XL on five, and XXS, 5XL and 6XL on one coat each. Runs are five to ten sizes, median six.
| Size | Coats offering it | Share of the range | A coat that carries it |
|---|---|---|---|
| XXS | 1 of 18 | 6% |  Snap Front Parka |
| XS | 10 of 18 | 56% |  Long Puffer Coat |
| S | 15 of 18 | 83% |  Double Collar Coat |
| M, L, XL, 2XL | 18 of 18 | 100% |  Shawl Hood Coat |
| 3XL | 10 of 18 | 56% |  Longline Cotton Jacket |
| 4XL | 5 of 18 | 28% |  Quilted Lining Overcoat |
| 5XL, 6XL | 1 of 18 | 6% | Long Puffer Coat |
Do I need to size up to wear a coat over a sweater?
Yes, by one letter. Adam & Westcott's published shirt charts add 1.6 inches of chest per step, and a sweater takes close to that, so one size up covers the layer without leaving the coat loose.
The catch is where your size sits in the run. Eight of the 18 coats stop at 2XL, so a 2XL buyer has no step up on those eight and should buy from the ten that go further.
Ten sizes, XS to 6XL, the only coat above 4XL, cut past the hips with room for a sweater underneath.
What if I need a 3XL or larger?
Ten of the 18 coats reach 3XL, five reach 4XL, and only the Long Puffer Coat carries 5XL and 6XL. Above 2XL the range narrows from 18 coats to ten, then five, then one.
The five that reach 4XL or beyond:
-
Long Puffer Coat, XS to 6XL, $99.99 -
Quilted Lining Overcoat, M to 4XL, $79.99 -
Funnel Neck Overcoat, M to 4XL, $79.99 -
Ardenlock Thermal Parka, XS to 4XL, $89.98 -
Ridgefall Corduroy Fleece Parka, XS to 4XL, $79.98
Knee length, quilted lining, clean two-button front, six sizes M to 4XL. The 18 coats run $39.99 to $139.98, median $79.99.
What if I take a small size?
Fifteen of the 18 coats carry S and ten carry XS, but only the Snap Front Parka carries XXS. Three start at M with no S at all, so check where the run begins.
The three starting at M are the 
Valoren Arctic Parka, the 
Funnel Neck Overcoat and the 
Quilted Lining Overcoat.
The only coat starting at XXS, seven sizes to 2XL, padded hood, four pockets, two snap flapped.
Coat sizing questions
What size coat should I buy if I am between sizes?
Size up. All 18 Adam & Westcott coats carry M, L, XL and 2XL, so the next letter is always there, and the extra 1.6 inches is room a coat should have.
Should I size up a coat to wear over a sweater?
One letter, not two. Each step in Adam & Westcott's published charts adds 1.6 inches in the chest, about what a mid-weight sweater occupies.
Does Adam & Westcott sell coats above 2XL?
Yes. Ten of the 18 coats reach 3XL, five reach 4XL, and the Long Puffer Coat carries 5XL and 6XL, the only coat above 4XL.
What is the smallest coat size available?
XXS, on the Snap Front Parka only. XS is on ten of the 18 and S on 15, while three coats start at M.
How much do Adam & Westcott coats cost?
From $39.99 to $139.98, median $79.99 across the 18 coats. Orders over $99 ship free.
Sizing the rest of your layers works the same way: What size jacket should I buy?, What size vest to wear over a sweater and the men's wool overcoat guide.
Find your size in this season's coats
Eighteen coats, XXS to 6XL, eight new in the last three weeks.
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