Suit Size Conversion Chart

US, UK and EU suit numbers

The US and UK suit systems share the same number, which is the chest measurement in inches. A suit listed as a US 40 and a suit listed as a UK 40 are both cut for about a 40 inch chest, so no conversion is needed between those two. The EU system uses a different number, roughly the chest in centimetres divided by two, which works out to about 10 higher than the US and UK number. As a general guide, add 10 to the US or UK number to get the EU number.

The table below gives the standard conversions from 34 to 50. Use it as general guidance, not as a guarantee, because brands grade differently and some EU makers round their numbers. When a listing gives both the number and the chest in inches or centimetres, trust the chest measurement over the converted number.

Letter sizes stay the same across systems

Letter sizes need no conversion at all, because XS, S, M, L, XL and XXL mean the same broad ranges in the US, the UK and the EU. A suit listed as M in any of the three systems is cut for about a 39 to 41 inch chest as a broad guide. This makes letter sizes the simplest way to shop across systems, though they are also the least precise, because each letter covers a range of two or three inches.

• XS covers about a 34 to 35 inch chest in all three systems.
• S covers about 36 to 38, M covers about 39 to 41, and L covers about 42 to 44.
• XL covers about 45 to 47 and XXL covers about 48 to 50.
• When a listing gives both a letter and a number, the number is the more precise of the two.

Jacket length letters: short, regular and long

Suit jackets also carry a length letter, usually S for short, R for regular and L for long, written after the size number, as in 40R or 42L. The length letter changes the jacket length and the sleeve length without changing the chest size. A 40S, a 40R and a 40L all fit about the same chest, but the jacket hem and the sleeve sit at different places. Some makers also use an extra short or extra long length for very short or very tall frames.

Length letters are broadly the same across the US, UK and EU systems, because they describe the same idea in each system. The exact jacket length behind each letter still varies by brand, so compare the stated jacket length with your own measurement rather than trusting the letter alone. Height is a rough guide to the length letter, but the hem and the sleeve are the real tests.

Trouser waist conversions

Suit trouser waists are usually listed in inches in the US and UK, so a 34 waist means about a 34 inch waist in both systems. EU trouser waists are usually listed in centimetres, so a 34 inch waist is about an 86 centimetre waist as a general guide. Multiply the inch waist by 2.54 to get centimetres, or divide the centimetre waist by 2.54 to get inches.

Some EU suits list the trouser waist as a size number rather than a measurement, and that number can follow the jacket size rather than the waist. When that happens, look for the waist in centimetres on the listing or the brand chart, because the size number alone will not tell you whether the trousers fit your waist. The broad trouser waist ranges in the suit size chart run from 28 to 29 inches at XS to 42 to 44 inches at XXL.

Ordering across systems without a mistake

1. Measure your chest and trouser waist in inches first, then convert only the listing, never your body.
2. Match the US or UK number to your chest, then add 10 for the EU number as a general guide.
3. Check the length letter separately, because a 40R and a 40L fit the same chest at different lengths.
4. Compare the stated chest, waist, sleeve and jacket length with your own numbers before ordering.
5. When a listing gives measurements in centimetres, divide by 2.54 to compare them with inches.