UK to US Men’s Clothing Size Converter

Convert UK men’s clothing sizes to US sizes instantly. The good news is that they’re the same: UK and US men’s numeric sizes are both simply the chest measured in inches, so a UK 40 is a US 40 and a UK 42 is a US 42 — a 1:1 match with nothing to add or subtract. This holds for jackets, suits and tailored shirts, where …

40

40 UK (numeric) = 40 US (numeric)  ·  chest ≈ 101.6 cm (40 in)

40 UK (numeric) IN EVERY SYSTEM

LETTER SIZE

REGIONAL NUMERIC

CHEST MEASUREMENT

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HOW TO USE

  1. 1

    Enter your UK men’s size in the value box — the converter defaults to UK (numeric) → US (numeric).

  2. 2

    Read the US size instantly — it’s the same number, since both are the chest in inches.

  3. 3

    Check the underlying chest measurement shown beneath, or tap ⇄ to convert US back to UK.

  4. 4

    Need another country? Switch to EU, Italy, France or the chest in cm in the dropdown, then Share or Embed.

QUICK REFERENCE

M

EU 48

M

US 38

L

EU 52

XL

US 46

US 40

EU 50

US 42

L

EU 50

US 40

Chest 42 in

L

S

EU 46

XL

Chest 46 in

ABOUT MEN’S CLOTHING SIZES

Almost every men’s clothing size is really a coded way of describing one measurement — the chest circumference — but each region codes it differently, and two different styles of code sit side by side. Casual clothes (T-shirts, sweaters, casual shirts) use letter sizes — XS, S, M, L, XL and up — which are the same letters worldwide but only ever describe a chest range, not an exact number. Tailored clothes (suits, blazers, dress shirts) use numeric sizes: in the US and UK the number is simply the chest measured in inches, so a 40 is a 40-inch chest, while most of continental Europe — Italy, France, Germany, Russia — adds ten, so that same chest is a EU 50. That is the whole trick: EU = US + 10, and US = chest in inches. Because a letter covers a two-inch-or-so band of chest, converting to a letter always snaps to the nearest one, and different brands cut an M or a 40 slightly differently. To use any of it well, measure your chest at its fullest point with the tape level and snug, then read across: a 96–cm (38–inch) chest is an M, a US 38 and a EU 48; a 107–cm (42–inch) chest is an L, a US 42 and a EU 52. Treat the letters as approximate, check the brand’s own chart when you can, and size up if you are between sizes or prefer a relaxed fit.

FREQUENTLY ASKED QUESTIONS

Yes. UK and US men’s numeric sizes are identical — both are the chest measured in inches — so a UK 40 is a US 40, and a UK 38 is a US 38. There is nothing to add or subtract.

  • UK size = US size (1:1).
  • Both are the chest in inches.
  • UK 40 = US 40.
  • UK 38 = US 38.

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Last updated: · 11 men’s clothing systems · Chest-based conversions (US/UK = chest inches; EU/IT/FR/DE/RU = US + 10); letter sizes are approximate · Verified by the EagleCalculator team · Eagle-eyed accuracy for every calculation.