Dress shirt size from neck and arm.

Worked example

A neck of 15.2 in rounds up to the next half inch: collar 15.5. EU size is 15.5 x 2.54 = 39.4, shown as 39, and 15.5 sits in the medium (M) band. An arm length of 33.4 in rounds up to a 34 in sleeve.

How it works

Collar size is the neck measurement rounded up to the next half inch. EU size is the collar in whole centimetres (16 in = 41). Sleeve is the arm length rounded up to a whole inch, measured from the centre back of the neck over the shoulder to the wrist bone.

Letter sizes follow the usual retail bands: 14 to 14.5 S, 15 to 15.5 M, 16 to 16.5 L, 17 to 17.5 XL and 18 to 18.5 XXL.

The finger of room is the comfort allowance: slide a finger under the tape when you measure and enter the number as read, because the calculator adds nothing more before rounding up to the next half inch. If you wear a tie or are between sizes, go up half an inch. Slim and athletic cuts change the body fit, not the collar number.

Sources and basis (checked 2026-10-05):

• EU shirt size = collar in centimetres and the S/M/L bands: the common retail size conversion tables. Checked 2026-10-05.
• Inch to centimetre: exactly 2.54 (NIST unit conversion).

FAQ

What is a 15.5 collar in EU size?

39. Multiply the collar in inches by 2.54 and round.

What size shirt is a 16 inch neck?

A 16 collar is EU 41 and typically L.

How do I measure my neck for a dress shirt?

Wrap a tape around the base of the neck where a collar sits, with a finger of room, and round up to the next half inch.

What is the sleeve length measurement?

From the centre back of the neck, across the shoulder to the wrist bone, with the arm slightly bent.

Should I go up a size if I wear a tie?

If between sizes, go up half an inch so the collar still closes comfortably.