Men's Clothing Size Conversion Guide

6 min read•June 1, 2025•Reviewed: June 1, 2026

✓Reviewed by Apex Conversion Editorial Team · Last reviewed June 1, 2026

Men's clothing sizing is more measurement-based than women's but still varies between countries. Suits use chest size in inches (US/UK) or centimeters (EU). Dress shirts use neck and sleeve in inches (US/UK) or collar in centimeters (EU). Trousers use waist and inseam in inches (US) or centimeters (EU).

The good news: because men's sizing is more directly tied to body measurements, conversions are more predictable than women's. Once you know your measurements in both inches and centimeters, finding your size in any system is straightforward.

Suit Size Comparison

US/UK  EU    Chest   Waist
─────  ──    ─────   ─────
  36   46    92cm    76cm
  38   48    97cm    81cm
  40   50   102cm    86cm
  42   52   107cm    91cm
  44   54   112cm    96cm
  46   56   117cm   101cm

Formula: EU suit = US/UK chest (inches) × 2 + 10
  US 40 suit: 40 × 2 + 10 = 90 ≈ EU 50

Dress Shirt Size Comparison

US/UK Neck  EU Collar  Sleeve (US)
──────────  ─────────  ───────────
  14.5       37cm       32/33
  15.0       38cm       32/33
  15.5       39/40cm    33/34
  16.0       41cm       34/35
  16.5       42cm       34/35
  17.0       43cm       35/36

Trouser and Jean Sizing

US and UK trousers use waist and inseam in inches (e.g., 32×30 = 32-inch waist, 30-inch inseam). EU trousers use waist in centimeters. To convert: multiply inches by 2.54. A 32-inch waist = 81 cm; a 34-inch waist = 86 cm.

European brands often sell trousers by a single EU size number (EU 48, EU 50) based on chest measurement for suits. For casual trousers, they may use waist in cm. When in doubt, look at the brand's specific measurement chart.

S/M/L vs Numeric Sizing

Many casual garments use S/M/L/XL rather than numeric sizes. These are not standardized — an XL from a US brand may be significantly larger than an XL from a Japanese brand. When buying casual clothing internationally, look for the brand's measurement guide.

As a rough guide: S ≈ EU 46–48, M ≈ EU 48–50, L ≈ EU 50–52, XL ≈ EU 52–54. These align with chest sizes of approximately 88–96 cm (S), 96–100 cm (M), 100–106 cm (L), and 106–112 cm (XL).

Quick Tips

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Suits: US/UK chest in inches × 2 gives approximate EU size (EU 50 = chest ~100 cm = ~39 inches).
✓
Dress shirts: multiply US neck size by 2.54 for EU collar in cm. 15.5 inches = 39.4 cm.
✓
Trousers: multiply waist inches by 2.54. 34-inch waist = 86 cm.
✓
For casual wear from Japanese brands, size up by at least one size from your usual S/M/L.

Frequently Asked Questions

What is a US men's suit size 40 in EU?

US 40 suit ≈ EU 50. The approximate formula: US chest (inches) × 2 + 10 ≈ EU size. 40 × 2 = 80, + 10 = 90... actually EU size ≈ US chest in cm. 40 inches = ~102 cm, and EU 50 = ~102 cm chest. Use the table above for accuracy.

What is a size 15.5 dress shirt in EU?

A US neck size 15.5 inches corresponds to EU collar 39–40 cm. Multiply inches by 2.54 for the cm equivalent.

Are US and UK men's suit sizes the same?

Yes — US and UK men's suit sizes use the same chest-in-inches scale. A US 40 suit and a UK 40 suit have the same chest measurement. They may differ in cut (British suits tend to be more structured; US suits often have a softer shoulder).

How do I measure my neck for a dress shirt?

Wrap a tape measure around the base of your neck, where the collar will sit. Add 0.5 inch (1.3 cm) for comfort. Round up to the nearest half-inch for US sizing. That is your collar size.

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