Shirt Collar Size Converter: Inches, cm, EU, UK/US

Shirt collar sizes measure the circumference of the neck, but different countries express this measurement in different units and scales.

Inches (UK / US) The traditional Anglo-American system. Collar size equals neck circumference in inches. Common sizes: 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18. UK and US collar sizing is identical, both use inches. Shirts are cut in half-inch steps, so 15.25 is not a size anyone sells.

EU Collar Size (European / Continental) Common in Europe and most other countries. Collar size equals neck circumference in centimeters. Common sizes: 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46. A size 40 EU shirt fits a 40 cm (15.75 inch) neck.

Centimeters The raw measurement in metric units. EU collar size and centimeter measurement are the same value. EU size 40 = 40 cm neck circumference.

Conversion formula:

• Inches → cm: multiply by 2.54
• cm → Inches: multiply by 0.3937
• EU size = neck circumference in cm (EU size and cm are identical)
• UK/US size = neck circumference in inches

How to measure your neck: Wrap a soft tape measure around the base of your neck, where a collar would sit. Keep one finger between the tape and your neck for comfort. Add 0.5 inches (1.3 cm) if you want a looser fit.

Common collar size conversions:

Note: EU sizes are sometimes rounded to the nearest whole centimeter on clothing labels. Always try shirts on when possible, as fit varies by brand and cut.

Why the chart skips EU 40 and 45 Look down the EU column above and you will notice it goes 39, then 41. Nothing is missing. The Anglo-American sizes move in half inches, which is 1.27 cm, so they land on the centimeter scale unevenly and occasionally step over a whole number. EU 40 is a 15.75 inch neck and EU 45 is 17.72, and neither is a size a British or American shirtmaker cuts. If you wear EU 40 and are shopping in inches, 15.5 will be a shade tight and 16 a shade loose. Take the 16 and let the collar be the comfortable one, because a shirt is worn buttoned and a half inch of slack at the neck disappears the moment you put a tie on.