Enter your US men's suit, jacket, or coat size to convert it to UK, EU, Japan sizes, and chest measurement in centimeters.
Men's Clothing Size Calculator
LiveThe conversion rules
US 42 jacket: UK 42, EU 52, Japan 44, chest approximately 106.7 cm, letter size Large. A US 34-inch waist pant converts to an EU 50 pant - a different rule than the jacket scale above.
A note on China
China isn't included as a single converted number, and that's a deliberate choice, not an oversight. Chinese men's clothing follows the GB/T 1335 standard, a height/chest/body-type code like "175/96A" (175cm tall, 96cm chest, standard build), rather than a single size number on the same scale as the US, UK, or EU systems. As a rough guide, a US Medium is often closer to a Chinese 2XL - Asian sizing commonly runs 2-3 letter sizes smaller than Western sizing for the same actual measurements. Comparing your chest measurement in centimeters (shown above) against the seller's specific chart is far more reliable than trusting any single converted number.
Step-by-step guide
- Measure your chest at the fullest point, or use your known US jacket/suit size.
- Select your US size above and read the equivalent UK, EU, and Japan sizes, plus the letter size.
- For pants specifically, use the separate waist-based rule (EU = US waist in inches + 16) rather than the jacket conversion.
Why jackets and pants use different rules
Jacket, suit, and coat sizes are based on chest measurement, while pants and trousers are sized by waist measurement - two different body measurements that don't scale the same way between countries. This is why a men's clothing converter needs separate rules for each garment type rather than one universal formula: converting a jacket size using the pants rule (or vice versa) gives a meaningfully wrong result, not just a slightly imprecise one.
Common mistakes
Frequently asked questions
Are UK and US men's clothing sizes really identical?
For jackets, suits, and letter sizes, yes - unlike women's clothing where the US and UK scales differ by about 4 sizes, men's clothing uses the same numbers in both countries.
How do dress shirt sizes work differently from jacket sizes?
Dress shirts are typically sized by neck circumference in inches (like 15, 15.5, 16) plus a sleeve length, rather than the chest-based jacket number - a separate measurement system from suit sizing entirely.
Why does the EU size look so much bigger than the US size?
European jacket sizing uses a different baseline that runs 10 higher than the US number for the same chest measurement - it isn't a bigger garment, just a different numbering convention describing the same size.
Why isn't China included as a simple converted size?
Chinese clothing uses a height/chest/body-type code (like 175/96A) rather than a single scaling number like the other systems here. A direct numeric conversion would imply false precision - comparing your chest measurement in centimeters against the specific seller's chart is more reliable.
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