Men's jackets and suits are sized by chest, and the number jumps between countries: a US 44 is an EU 54. Enter a men's US size, a European size, or a women's size, and we will give you the equivalents, including the men's to women's crossover, which is an approximation because the two are cut very differently.
Jacket and suit sizing looks chaotic across borders, but underneath it is one honest number: your chest in inches. Everything else is that number in a different costume. A US 44, a UK 44, an EU and Italian 54, and a casual XL are all the same jacket. This page translates between all of them, and does the men's to women's crossover that trips people up, with the caveat that crossover deserves.
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How jacket and suit sizing works
A men's jacket or suit is tagged by the chest measurement it is cut for, in inches, rounded to an even number: a 40 is built for a 40 inch chest. The UK uses the same number. Europe and Italy add 10, so that same jacket is a 50 there. Casual jackets collapse the range into S, M, L. And US suits add a length letter for your height (S, R or L), which is a separate axis from the chest number entirely. Once you see that the chest inch is the anchor, the rest is arithmetic.
The method
men's US = men's UK = chest in inches (even)
men's EU = men's IT = US + 10
casual letter: 34 XS, 36 to 38 S, 40 M, 42 L, 44 XL, 46 to 48 XXL
Women's sizing does not convert cleanly from men's, because the garments are cut differently through the shoulder, waist and sleeve. The women's column on this page is an approximate crossover by chest, useful for buying a men's or boyfriend-cut jacket, and it is deliberately shown as a range rather than a false single number.
Worked example
You find a jacket labelled 54 and want to know if it is your size. A 54 is a European suit size. Subtract 10 for the US and UK size: a 44. That is an XL in casual terms, and it aims at a 44 inch chest. Across to women's it is roughly a 16 to 18, though a woman buying it would find the shoulders wide and the waist straight, because it was cut for a man's frame.
Full jacket and suit conversion chart
The chest inch is the body measurement each size is cut for. Brands add their own ease, and Italian cuts run trim while American cuts run full, so use this as the map.
| Chest (in) | US / UK | EU / IT | Casual | Women's US (approx) |
|---|
| 34 | 34 | 44 | XS | 6 to 8 |
| 36 | 36 | 46 | S | 8 to 10 |
| 38 | 38 | 48 | S | 10 to 12 |
| 40 | 40 | 50 | M | 12 to 14 |
| 42 | 42 | 52 | L | 14 to 16 |
| 44 | 44 | 54 | XL | 16 to 18 |
| 46 | 46 | 56 | XXL | 18 to 20 |
| 48 | 48 | 58 | XXL | 20 to 22 |
| 50 | 50 | 60 | 3XL | 22 to 24 |
| 52 | 52 | 62 | 3XL | 24 or larger |
Length: the letter that is not S, M or L
A US suit jacket carries a second letter you cannot ignore: the length. R is regular, cut for roughly 5 feet 8 inches to 6 feet tall. S is short, for under about 5 feet 8. L is long, for about 6 feet 1 and up, and some brands add XL for taller still. A 40S, 40R and 40L all fit the same 40 inch chest but differ in body length and sleeve, so a tall man in a 40R will find the sleeves and hem short even though the chest is right. Get the chest number first, then the length for your height. This is a different thing from the casual S, M, L in the chart above, which describes the chest.
Men's to women's, honestly
People search this constantly, usually to buy an oversized or boyfriend-cut blazer, so here is the honest version. By chest inches alone, a men's 38 is about a women's 10 to 12, a men's 40 about a 12 to 14, a men's 42 about a 14 to 16. But a jacket is not a tube. Men's jackets are built with wider, more padded shoulders, a straight waist, and longer sleeves and body, so even at the matching chest number a men's jacket wears boxier and longer on a woman's frame, which is exactly the relaxed look if that is what you are after. Use the range as your starting size, then judge it in the mirror at the shoulders, which are the one seam a tailor cannot easily move. The reverse, a woman sizing into structured menswear, follows the same ranges backward.
Frequently asked questions
What is my US jacket size in EU?
Add 10. Men's suit and jacket sizes in Europe and Italy are the US chest size plus 10, so a US 40 is an EU 50, a US 44 is an EU 54, and a US 38 is an EU 48. The UK uses the same number as the US, so a US 40 is a UK 40. Going the other way, subtract 10: a size 54 suit is a US 44.
How do men's jacket sizes convert to women's?
Only approximately, because men's and women's jackets are cut completely differently, with different shoulder width, waist shaping and sleeve. As a rough crossover by chest, a men's 38 is about a women's 10 to 12, a men's 40 about a women's 12 to 14, and a men's 42 about a women's 14 to 16. Treat it as a starting point for buying a men's or boyfriend-cut jacket, not a guarantee of fit.
What does the R, S or L after a jacket size mean?
It is the length, for your height, and it is separate from the chest number and from casual S/M/L sizing. R is regular, for roughly 5 feet 8 inches to 6 feet; S is short, for under about 5 feet 8; L is long, for about 6 feet 1 and up. So a 40R and a 40L have the same chest but different body and sleeve length. Get the chest number right first, then pick the length letter for your height.
What size is a 54 suit?
A size 54 is a European or Italian suit size, which converts to a US and UK 44 (54 minus 10). In casual terms that is about an XL. If a listing shows both, a 54 and a 44 on the same jacket are the same garment in two sizing systems, not two different sizes.
Is a suit size the same as a jacket size?
The jacket is, yes. A suit is sold by its jacket size, so a 40R suit has a 40R jacket, and the trousers come sized to a matching waist (usually the jacket number minus about 6 inches, so a 40 jacket pairs with roughly a 34 waist trouser, which is called the drop). Separates let you buy a different trouser waist when your drop is not standard.
How do I measure my chest for a jacket?
Wrap a soft tape around the fullest part of your chest, under your arms and across the shoulder blades, over a shirt but not a jumper. Keep it level and snug, and breathe normally rather than puffing out. That measurement in inches is your US and UK jacket size, rounded to the nearest even number. No soft tape? Run a piece of string the same way, mark the overlap, and measure it against a ruler.
Why does the same jacket size fit differently by brand?
Because the chest number is the body measurement the jacket is cut for, not the finished garment, and every brand adds its own amount of ease and its own cut. Italian jackets tend to run trim and short, American cuts fuller, so the same 40R varies. The number gets you to the right rack; the mirror settles the rest, especially in the shoulders, which are the one part a tailor cannot easily change.