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UK to US Suit Size Conversion

US/UK Chest (in)US/UK Chest (in)
3636
3838
4040
4242
4444
4646
4848

Sizing conventions vary by brand and by cut — this table shows the standard published conversion. Always check the garment's own size chart when one is available. See how these tables are compiled.

Reversed, a UK 42 suit is a US 42 — no numeric conversion needed, since both countries size by the same chest-inch measurement, making this page mainly a confirmation for a UK buyer ordering from a US tailor or retailer.

What's worth checking instead of the size number is drop and shoulder structure, since US suit brands have traditionally cut a roomier, less structured jacket than the UK tailoring tradition at the same nominal chest size.

Frequently asked questions

What should I actually check buying a US suit as a UK size 42?

The jacket's cut and shoulder structure, not the size number — US suits at the same chest measurement have traditionally been cut roomier and less structured than UK tailoring.