Dress Shirt Size Calculator
Measure your neck for the collar size that fits, with US/UK inches, EU centimetres and S/M/L.
Find your collar size
How to measure
Measure your neck
Wrap a soft tape around the base of your neck where the collar sits, with one finger under the tape for room.
Round to the half inch
Collar sizes step in half inches (15, 15½, 16…). We add a little ease so the top button isn't tight.
Slim vs regular fit
Collar size sets the neck; choose slim or regular fit for the body separately.
S/M/L casual shirts
Casual shirts use S/M/L — the letter equivalent is shown alongside.
Frequently asked questions
What collar size is a 39 cm neck?
About a 15½ inch collar (EU 39), which is a Medium in S/M/L shirts.
How should a dress shirt collar fit?
You should be able to slide one finger between the buttoned collar and your neck — snug but not tight.
How this is calculated
Collar size is your neck circumference with a small amount of ease, rounded to the nearest half inch — so a 39 cm neck is about a 15½ collar. The EU size is that figure in centimetres. S/M/L bands follow the standard collar ranges.
Sources: Standard dress-shirt collar sizing (neck circumference + ease, half-inch steps), 2026.