The short answer
Suit jacket sizes in the US and UK are your chest measurement in inches, followed by a length: S (short), R (regular) or L (long). A 40R fits a 40-inch (102 cm) chest at average height. European and Italian sizes are usually the US size plus 10, so a 40 becomes a 50. Standard suit trousers are 6 inches (15 cm) smaller than the jacket.
- US and UK jacket size = chest in inches: a 40-inch (102 cm) chest wears a 40
- European and Italian sizes are usually the US or UK size plus 10 (US 40 = EU 50)
- S, R and L set the body and sleeve length, chosen mainly by height
- Standard drop is 6: a 40 jacket comes with 34-inch (86 cm) trousers
- Brands vary, so check each brand's own chart and garment measurements
- Between sizes, choose by the shoulders and alter the rest
In this guide
- What does 40R mean in suits?
- Suit size chart: US, UK, EU and Italian sizes
- Short, regular or long: which length are you?
- What is a suit drop, and how do jacket sizes relate to trouser sizes?
- How to find your suit size
- What size suit am I based on height and weight?
- What if you are between suit sizes?
- UK, European and Italian suit sizes
- Buying a suit online: how to get the size right
- Why suit sizes vary between brands
- The tailor's view: a size is a starting point
- Questions people ask
A suit size chart turns three numbers into a size: your chest, your height and your trouser waist. Once you know how the system works, you can read a 40R, a 52L or a 38S at any shop in the world and know roughly what will fit before you try it on. What a chart cannot tell you is how a particular brand cuts, so the sections on brand variation and in-between sizes matter as much as the chart itself.
What does 40R mean in suits?
40R means a jacket made for a 40-inch (102 cm) chest in a regular length. The number is the chest measurement in inches; the letter is the length of the body and sleeves: S for short, R for regular, L for long. So a 42L is a jacket for a 42-inch (107 cm) chest, cut longer for a taller man, and a 38S is for a 38-inch (97 cm) chest, cut shorter.
| On the label | What it means |
|---|---|
| 40 | Jacket for a 40-inch (102 cm) chest, in US and UK sizing |
| 50 | The European and Italian equivalent of a US or UK 40 |
| S, R, L | Short, regular or long: the length of the jacket body and sleeves |
| XL | Extra long (not extra large) on a suit jacket |
| 40R / 34W | A 40 regular jacket sold with 34-inch (86 cm) waist trousers |
| Drop 6 | The trousers are 6 inches (15 cm) smaller at the waist than the jacket chest |
| Slim, tailored, classic | The cut, not the size: how much room the brand builds in |
Suit size chart: US, UK, EU and Italian sizes
US and UK jacket sizes are the same: the chest measurement in inches. European and Italian sizes are usually the US or UK size plus 10, which in the middle of the range is close to half the chest measurement in centimeters. The trouser waist in the last column assumes the standard drop of 6.
| US / UK jacket | Chest | EU / Italian | Trouser waist (drop 6) |
|---|---|---|---|
| 34 | 34 inches (86 cm) | 44 | 28 inches (71 cm) |
| 36 | 36 inches (91 cm) | 46 | 30 inches (76 cm) |
| 38 | 38 inches (97 cm) | 48 | 32 inches (81 cm) |
| 40 | 40 inches (102 cm) | 50 | 34 inches (86 cm) |
| 42 | 42 inches (107 cm) | 52 | 36 inches (91 cm) |
| 44 | 44 inches (112 cm) | 54 | 38 inches (97 cm) |
| 46 | 46 inches (117 cm) | 56 | 40 inches (102 cm) |
| 48 | 48 inches (122 cm) | 58 | 42 inches (107 cm) |
| 50 | 50 inches (127 cm) | 60 | 44 inches (112 cm) |
| 52 | 52 inches (132 cm) | 62 | 46 inches (117 cm) |
| 54 | 54 inches (137 cm) | 64 | 48 inches (122 cm) |
Chest is the body measurement, not the jacket's. Brands vary in how they cut each size, and some use a smaller drop in larger sizes, so always check the brand's own chart.
Short, regular or long: which length are you?
The letter after the number sets the length of the jacket body and sleeves, and you choose it mainly by height. Each step up in length usually adds about an inch (2.5 cm) to the body, with the sleeves lengthened to match, though the exact difference varies by brand. Brands also draw the height lines differently, often by an inch or two, so treat the ranges as a guide.
| Length | Label | Typical height |
|---|---|---|
| Short | S | About 5 ft 7 in (170 cm) and under |
| Regular | R | About 5 ft 8 in to 5 ft 11 in (173 to 180 cm) |
| Long | L | About 6 ft to 6 ft 3 in (183 to 191 cm) |
| Extra long | XL | About 6 ft 4 in (193 cm) and over |
Brands set their own ranges. If you are near a boundary, try both lengths.
Short (S)
About 163 to 170 cm
64–67 in
Regular (R)
About 173 to 180 cm
68–71 in
Long (L)
About 183 to 191 cm
72–75 in
Extra long (XL)
About 193 cm and over
76–79 in
Height is a shortcut for what really matters: whether the jacket covers your seat and whether the sleeves reach your wrists. A man of 5 ft 11 in (180 cm) with long arms or a long torso may need a long; a man of 6 ft (183 cm) with short arms may be better in a regular with the sleeves let down. Check the length rules in how long a suit jacket should be when you try the suit on.
What is a suit drop, and how do jacket sizes relate to trouser sizes?
The drop is the difference between the jacket chest size and the trouser waist size. The standard drop is 6, meaning the trouser waist is 6 inches (15 cm) smaller than the jacket chest: a 40 jacket comes with 34-inch (86 cm) trousers, a 42 with 36-inch (91 cm) trousers. Some cuts use a different drop to suit a different build.
| Drop | Trousers with a 40 jacket | Where you see it | Suits |
|---|---|---|---|
| 4 inches (10 cm) | 36 inches (91 cm) | Some portly or executive cuts | A waist close to the chest measurement |
| 6 inches (15 cm) | 34 inches (86 cm) | Standard for most suits | An average build |
| 7 inches (18 cm) | 33 inches (84 cm) | Some slim and modern fits | A slimmer waist |
| 8 inches (20 cm) | 32 inches (81 cm) | Some athletic fits | A broad chest and narrow waist |
To find your own drop, subtract your trouser waist from your chest. A man with a 42-inch (107 cm) chest and a 34-inch (86 cm) trouser waist has a drop of 8: a standard 42R would come with trousers 2 inches (5 cm) too big, while an athletic cut with a drop of 8 would fit both. A man with a 42-inch chest and a 38-inch (97 cm) waist has a drop of 4, and would need the trousers of a standard suit let out beyond what most seams allow.
If your own drop is different from the suit's, you have three options. A tailor can usually take in or let out the trouser waist by about 1 inch (2.5 cm). Some brands sell suit separates, so you can buy the jacket and trousers in different sizes. Or you can look for a cut with the drop you need, such as an athletic fit for a large drop. When a suit is sold as a set, choose by the jacket: it is far harder to alter than the trousers.
How to find your suit size
Finding your suit size in five steps
- 1
Measure your chest
Wrap a soft tape around the fullest part of your chest, under the armpits, keeping it level and snug, and measure at the end of a normal breath. Step-by-step instructions are in how to measure yourself for a suit.
Tip: Measure over a thin shirt, never a sweater. Bulky clothing can add a full size.
- 2
Turn it into a jacket size
Your chest in inches is your US or UK size; add 10 for the usual European size. Most suits come in even sizes, so if you measure 41 inches (104 cm), try both a 40 and a 42.
- 3
Choose the length
Use the height ranges as a starting point: short, regular, long or extra long.
- 4
Check the trousers
Measure your trouser waist where you wear your trousers. Compare it with the suit's drop; if it differs by more than about an inch (2.5 cm), look at separates or a different cut.
- 5
Try it on and judge the shoulders
The shoulder seam should end at your shoulder bone, with no dent or ridge at the top of the sleeve. If the shoulders fit, the rest can usually be altered.
What size suit am I based on height and weight?
Height tells you your length, but weight is a poor guide to your jacket size. Two men of the same height and weight can carry it very differently: one in the chest and shoulders, another at the waist. The first may need a larger jacket with a bigger drop, the second a smaller jacket with a smaller drop. Online calculators that use height and weight give a rough starting point at best.
Your chest measurement is the reliable figure. If you cannot measure yourself, measure a jacket that fits you: button it, lay it flat, measure across the chest from armpit to armpit and double it. Because jackets are cut larger than the body they fit, subtract the room built into the cut, about 3 to 6 inches (8 to 15 cm) depending on whether it is slim or classic, to estimate the chest size it was made for.
What if you are between suit sizes?
When you fall between two sizes, choose by the shoulders. They are the hardest part of a jacket to alter, while the waist, sleeves and trousers are routine work for a tailor.
| Size up if | Size down if |
|---|---|
| The smaller size pulls at the shoulders or the button; a tailor can take in the waist and shorten the sleeves | The larger size's shoulders overhang your shoulder bones and dent |
| You have a broad back or big arms; ready-to-wear seams carry little fabric to let out | The larger collar stands away from your neck |
| You plan to wear the jacket over a fine knit | The larger jacket falls well past your seat |
Trousers follow the same logic. If your waist falls between two trouser sizes, the larger pair can usually be taken in by about 1 inch (2.5 cm) at the center back seam. Check the seat and thighs as well as the waist, because those are harder to adjust than the waistband.
UK, European and Italian suit sizes
UK jacket sizes use the same chest-in-inches numbers as the US, with the same S, R and L lengths, and UK trouser sizes are the waist in inches. European and Italian sizes use a different scale, usually the US or UK size plus 10: a 38 is a 48, a 40 is a 50, a 42 is a 52. In the middle of the range the European number is also close to half your chest in centimeters, so a 100 cm (39 inch) chest points to a 50; at larger sizes the two methods drift apart, which is another reason to check the brand's chart.
Some European brands add their own variations, including separate numbers for short and long fits, so read the brand's chart rather than assuming the plus-10 rule. And remember that the number system is shared but the cut is not: two brands' size 50 can fit quite differently.
Buying a suit online: how to get the size right
Buying online removes the fitting room, so the numbers have to do the work. The most reliable method is to compare the brand's garment measurements with a jacket and trousers you already own that fit well. A size chart tells you the body a suit is meant for; garment measurements tell you what you will actually receive.
Before you order a suit online
- Your chest, waist and trouser waist measured in the last few months
- The brand's own size chart checked, not a general one
- Garment measurements compared with a jacket and trousers that fit you: chest, shoulder width, sleeve, back length, trouser waist and leg opening
- The fit label understood: slim, tailored and classic change the room, not the size
- The drop checked against your own chest-to-waist difference
- The returns policy read, including whether altered or hemmed items can be returned
- Trousers left unhemmed, or the inseam confirmed, before any finishing is done
If you are unsure between two sizes and the retailer allows free returns, order both, keep the one whose shoulders fit, and return the other unworn. Leave all alterations until you have decided.
Why suit sizes vary between brands
A size names the body a suit is meant for, not the suit's own measurements. Each brand decides how much room to build in, how the shoulders are shaped, how long each length is and which drop to use. Fit labels add another layer: a slim fit 40 and a classic fit 40 from the same brand differ in chest room by several inches, as explained in slim vs tailored vs classic fit.
Trouser sizes can drift too. Some brands, particularly in casual trousers, label a waist smaller than it measures, so a pair marked 34 may measure larger. Measure the waistband of trousers that fit you and compare it with the brand's garment measurements if they are published.
The tailor's view: a size is a starting point
To a tailor, your size only gets you to the right rail. Ready-to-wear suits are cut for an average body in each size, and almost everyone needs at least the trousers hemmed and often the sleeves adjusted. Made-to-measure starts from a base size and alters the pattern to your measurements. Bespoke has no sizes at all: the pattern is drafted for you.
Whatever the route, the size is right when the shoulders, collar and jacket length fit, because those are the hard parts to change. The full checklist is in how a suit should fit, and the jobs a tailor can realistically do afterwards are listed in what a tailor can and can't alter.
Questions people ask
What does 40R mean in suits?
40R means a jacket for a 40-inch (102 cm) chest in a regular length. The number is the chest measurement in inches and the letter is the length: S for short, R for regular, L for long. On a standard suit, a 40R comes with 34-inch (86 cm) trousers.
What size suit am I based on height and weight?
Height sets your length (short, regular or long), but weight does not reliably predict your jacket size, because build varies so much. Measure your chest instead: the figure in inches is roughly your US or UK size. If you cannot measure yourself, measure a jacket that fits you well.
What is the difference between short, regular and long suits?
Short, regular and long suits share the same chest size but differ in the length of the jacket body and sleeves, usually by about an inch (2.5 cm) in body length per step. Short typically suits men up to about 5 ft 7 in (170 cm), regular about 5 ft 8 in to 5 ft 11 in (173 to 180 cm) and long about 6 ft to 6 ft 3 in (183 to 191 cm). Brands set their own ranges.
How do suit jacket sizes relate to trouser sizes?
On a standard suit the trouser waist is 6 inches (15 cm) smaller than the jacket chest, a difference called the drop. A 40 jacket comes with 34-inch trousers and a 42 with 36-inch trousers. Some slim and athletic fits use a drop of 7 or 8, and some portly cuts a drop of 4.
What is a US 42L in European sizes?
A US 42L is usually a European or Italian 52, in a long length. European sizes are generally the US or UK size plus 10. Brands label long lengths in different ways, so check the brand's own chart.
Are UK and US suit sizes the same?
Yes, for jackets. Both use the chest measurement in inches with short, regular and long lengths, so a UK 40R is a US 40R. Trouser waists are also given in inches in both.
Should I size up or down if I am between suit sizes?
Choose the size whose shoulders fit. If both fit at the shoulders, the larger size is usually safer, because a tailor can take in a jacket more easily than let it out. Size down only if the larger size overhangs your shoulders or its collar stands away from your neck.
What does XL mean on a suit?
On a suit jacket, XL usually means extra long, a length for men of about 6 ft 4 in (193 cm) and over, not extra large. The chest size is still given by the number, as in 44XL. Check the brand's chart to be sure.
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