Shirts size calculator
Shirt sizes & collar size
A dress shirt is sized by its collar. Convert centimeters, inches and letter sizes, or work out your collar size straight from your neck measurement.
Shirt sizes conversion: the short answer
The shirt size is the collar size in centimeters. In the UK and the US it is given in inches instead (cm ÷ 2.54): 40 cm = 15¾ inches, 41 cm = 16 inches, 43 cm = 17 inches. Your collar size is your neck measurement plus about 1 cm.
Shirt size chart: collar in cm, inches and S–XL
| Inch | cm | INT |
|---|---|---|
| 14 | 36 | XS |
| 14½ | 37 | S |
| 15 | 38 | S |
| 15½ | 39 | M |
| 15¾ | 40 | M |
| 16 | 41 | L |
| 16½ | 42 | L |
| 17 | 43 | XL |
| 17½ | 44 | XL |
| 17¾ | 45 | XXL |
| 18 | 46 | XXL |
| 18½ | 47 | 3XL |
| 19 | 48 | 3XL |
Letter sizes usually cover two collar sizes at once (for example M = 39/40).
- Inch – Collar size in inches (US, UK)
- cm – Collar size in centimeters (EU)
- INT – Letter sizes (XS–3XL)
Read the collar size off a shirt
No tape measure handy? Take a shirt whose collar fits well:
- Unbutton the collar and lay it flat on the table.
- Measure from the center of the top button to the outer end of the buttonhole.
- The result in cm is your collar size. It is usually printed inside the collar or on the label too.
Fit: slim, regular or comfort
Besides the collar size, the cut decides how a shirt sits on your upper body:
- Slim fit / body fit: strongly tapered, for a slim torso.
- Regular / modern fit: lightly tapered, the all-rounder.
- Comfort / classic fit: cut straight, with plenty of room to move.
The collar size stays the same in every fit — only the width at chest and waist changes.
Sleeve length
In Germany, sleeve length is measured from the shoulder seam to the end of the cuff. Many makers offer extra-long sleeves alongside the standard length for tall men. In the US, sleeve length is measured from the middle of the back of the neck, over the shoulder and down to the wrist — which is why the number is much larger. Our guide to measuring your arm length shows how it works.
Tips for getting the size right
The two-finger rule
With the collar buttoned, two fingers should slide flat between collar and neck. If only one fits, the collar is too tight.
Wearing a tie?
If the shirt is worn with a tie, do not cut the collar close — a tight collar throws wrinkles.
Allow for shrinkage
Cotton shirts can shrink slightly in the first few washes. Non-iron finishes hold their shape better.
FAQ about shirt sizes
What collar size do I need?
Measure your neck at the level of the Adam's apple and add about 1 cm. With a 39 cm neck, collar size 40 is right.
What collar size is a medium?
An M is usually collar size 39/40, an L is 41/42 and an XL is 43/44.
What does shirt size 15½ mean?
15½ is the collar size in inches and works out to 39 cm.
What does shirt size 16 mean?
16 inches is a collar size of 41 cm (an L in letter sizing).