Men's Suit Size Conversion: US to EU Jacket Guide
Convert men's suit and blazer sizes between US, UK and EU jacket systems. Includes chest measurement, short/regular/long lengths and international sizing equivalents for a perfect fit.
Men's suit sizing can be confusing because the United States, United Kingdom and Europe each use a different numbering system for jacket sizes. In the US, suit sizes are based directly on chest circumference in inches, so a 40-inch chest means a size 40 jacket. EU suit sizes use half the chest circumference in centimeters, making a US 38 roughly equivalent to an EU 48. UK sizing typically follows US numbers but uses a slightly different cut. Our Suit/Blazer Size Converter handles the conversion between all three systems instantly.
US Suit Numbers vs EU Suit Numbers
The general rule for converting US suit size to EU is to add 10 to the US number: a US 36 becomes an EU 46, a US 40 becomes an EU 50, and a US 44 becomes an EU 54. However, this is only a rough starting point because different brands interpret the EU standard slightly differently. Italian and French suit makers often cut slimmer than German or British brands even when the tagged EU number is the same, so checking the actual chest measurement in centimeters is more reliable than relying on the conversion math alone.
Short, Regular and Long Jacket Lengths
Beyond the chest number, suit jackets are offered in short, regular and long lengths to accommodate different heights. A man who is 5 foot 7 with a 42-inch chest might wear a 42 short, while someone who is 6 foot 2 with the same chest needs a 42 long. EU suit sizing sometimes encodes length into the size number itself — for example, an EU 50 Lang (long) — but more often uses a separate letter suffix. Our Suit/Blazer Size Converter includes both chest and length options so you can find the exact combination for your build.
Measuring Your Chest for a Suit Jacket
To measure your chest for suit sizing, stand up straight with your arms relaxed at your sides. Wrap a measuring tape around the fullest part of your chest — typically just under the armpits and across the shoulder blades at the front. The tape should be snug enough to stay in place without pulling tight. Round up to the nearest whole inch, and add 4 to 6 inches if you are ordering a suit that will be tailored down, which gives the tailor enough fabric to work with for a custom fit.