The Challenge
European dress shirts list collar sizes in centimeters — a size 41 collar is 41cm neck circumference. US and UK shirts use inches: that same shirt is a size 16. Buy the wrong one and the collar either chokes you or gaps at the button. The conversion is straightforward: divide centimeters by 2.54. A 38cm collar = 15 inches, a 41cm collar = 16.1 inches (sold as size 16), a 43cm collar = 16.9 inches (sold as 17). Most brands round to the nearest half inch, so a 42cm neck sits between sizes — size up if you wear a tie, size down for casual wear.
Collar Size Conversion Chart: cm to Inches
| EU Size (cm) | Inches (exact) | US/UK Size | General Fit |
|---|---|---|---|
| 36 cm | 14.17 in | 14 | XS |
| 37 cm | 14.57 in | 14½ | S |
| 38 cm | 14.96 in | 15 | S |
| 39 cm | 15.35 in | 15½ | M |
| 40 cm | 15.75 in | 15½–16 | M |
| 41 cm | 16.14 in | 16 | L |
| 42 cm | 16.54 in | 16½ | L |
| 43 cm | 16.93 in | 17 | XL |
| 44 cm | 17.32 in | 17½ | XL |
| 45 cm | 17.72 in | 17¾–18 | XXL |
| 46 cm | 18.11 in | 18 | XXL |
| 47 cm | 18.50 in | 18½ | 3XL |
| 48 cm | 18.90 in | 19 | 3XL |
Brand Size Label Differences
| Neck Measurement | Charles Tyrwhitt | Brooks Brothers | Hugo Boss | Zara |
|---|---|---|---|---|
| 39–40 cm | 15½ | 15½ | 39/40 | M |
| 40–41 cm | 16 | 16 | 40/41 | M–L |
| 41–42 cm | 16½ | 16½ | 41/42 | L |
| 42–43 cm | 17 | 17 | 42/43 | XL |
| 43–44 cm | 17½ | 17½ | 43/44 | XL |
How to Find Your Collar Size in Inches from a EU Shirt Label
- Find the number on the EU shirt label — this is the collar circumference in centimeters
- Divide by 2.54: a size 42 label → 42 ÷ 2.54 = 16.54 inches
- Round to the nearest half inch: 16.54 rounds to 16½
- Cross-check against the chart — if the shirt is a slim or Italian cut, consider going half a size up
Collar Size Is Not the Same as Chest Size
A size 41/42 collar label on a European shirt tells you the neck size only — not the chest or body fit. Two shirts with identical collar sizes can have wildly different body widths depending on whether they're cut slim, regular, or relaxed. Always check both collar and chest measurements when buying internationally.
EU Collar Sizing vs US Collar Sizing
Step-by-Step Workflow
Measure neck circumference in cm at the collar bone base
Divide by 2.54 to get inches — or enter the value above
Match to the nearest half-inch US size in the chart below
Specifications
- Formula
- inches = centimeters ÷ 2.54
- 38 cm collar
- 15.0 in (US size 15)
- 39 cm collar
- 15.4 in (US size 15½)
- 41 cm collar
- 16.1 in (US size 16)
- 43 cm collar
- 16.9 in (US size 17)
- Measuring point
- around neck base, 2 fingers clearance
- Rounding rule
- ties → size up; casual → size down
Best Practices
- Measure with a flexible tape at the base of the neck, not the throat — add 1–2cm ease for comfort
- EU collar numbers are the neck circumference in cm — size 41 literally means 41cm
- If between sizes, go up for formal shirts with ties, down for casual open-collar wear
- Italian brands (Borriello, Finamore) cut smaller — add 1cm to your measured size
- Shrinkage: cotton dress shirts lose 1–2cm after first wash; size up if buying pre-wash
Frequently Asked Questions
What is a size 41 collar in inches?
A size 41 collar is 41cm neck circumference, which equals 41 ÷ 2.54 = 16.14 inches. US shirts sell this as size 16. If you're between 16 and 16½, a 41cm neck fits a size 16 for casual shirts and a size 16½ for dress shirts worn with a tie.
How do I convert EU shirt collar size to US?
EU collar sizes are neck circumference in centimeters. Divide by 2.54 to get inches, then round to the nearest half inch: 36cm=14in, 37cm=14½in, 38cm=15in, 39cm=15½in, 40cm=15¾in (sold as 16), 41cm=16in, 42cm=16½in, 43cm=17in, 44cm=17½in, 45cm=17¾in (sold as 18).
How do I measure my collar size at home?
Use a flexible tape measure around the base of your neck, where a collar would sit. Keep two fingers between the tape and your neck for a comfortable fit measurement. Read in centimeters for EU sizing, inches for US. Neck circumference fluctuates slightly — measure in the evening when your body is at its largest.
What collar size is a medium shirt in cm?
A medium shirt typically corresponds to a 39–40cm collar (15½ inches). S = 37–38cm (14½–15in), M = 39–40cm (15½in), L = 41–42cm (16–16½in), XL = 43–44cm (17–17½in), XXL = 45–46cm (17¾–18in). These ranges vary by brand — fitted shirts cut 1cm smaller than relaxed fits at the same labeled size.
Why don't collar sizes match exactly between EU and US?
EU collar sizes are the actual neck measurement in whole centimeters. US sizes are in half-inch increments. Since 1cm ≠ an exact number of half inches, the mapping isn't perfect — 40cm = 15.75 inches, which falls between US sizes 15½ and 16. Brands handle this differently: some label 40cm as 15½, others as 16.