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Men’s shirt collar sizes: inches, centimetres and EU
An EU shirt size is the collar in centimetres: a 15.5 inch collar is an EU 39, and a 16 inch collar is an EU 41. UK and US shirts both use inches, so a UK 16 collar is a US 16.
This page is for formal shirts sized by collar. Casual shirts sized S, M and L follow the brand’s own chest chart.
By Sienna Stones · Published 12 November 2026
Shirt collar size chart
| UK / US collar (in) | Collar (cm) | EU shirt size |
|---|---|---|
| 14.5 | 37 | 37 |
| 15 | 38 | 38 |
| 15.5 | 39.5 | 39 |
| 16 | 40.5 | 41 |
| 16.5 | 42 | 42 |
| 17 | 43–43.5 | 43 |
| 17.5 | 44.5 | 44–44.5 |
| 18 | 45.5 | 45.5–46 |
Each collar size in EU sizes
- 14.5 inch collar is 37 cm and an EU 37.
- 15 inch collar is 38 cm and an EU 38.
- 15.5 inch collar is 39.5 cm and an EU 39.
- 16 inch collar is 40.5 cm and an EU 41.
- 16.5 inch collar is 42 cm and an EU 42.
- 17 inch collar is 43–43.5 cm and an EU 43.
- 17.5 inch collar is 44.5 cm and an EU 44–44.5.
- 18 inch collar is 45.5 cm and an EU 45.5–46.
Where the charts disagree
- Rounding: EU shirt sizes are rounded centimetres, so 16 inches (40.5 cm) is printed as EU 41 in our sources. Where a brand prints centimetres, use that figure.
- 17 and above: our sources print a 17 inch collar as 43 to 43.5 cm and a 17.5 inch collar as EU 44 to 44.5.
- Fit names: a slim and a classic shirt with the same collar size have very different chests. Check the brand’s chest measurement too.
How to measure yourself
A conversion only shortlists a size. Your own measurements, checked against the brand's size chart, decide it.
- Chest: measure around the fullest part of your chest, under your arms, with the tape level.
- Collar: measure around the base of your neck where a shirt collar sits, with one finger under the tape.
- Waist: measure where you wear your trousers, not your natural waist, unless the brand says otherwise.
Then check whether the brand's chart shows body or garment measurements. Our explainer on what "true to size" means covers fit notes such as "slim fit".
A note for merchants
Shoppers search for conversions because a single size label does not tell them how an item will fit. If you sell clothes or shoes online, publish a size chart in centimetres for each product, say whether it shows body or garment measurements, and add a short fit note. A free size chart template is a quick place to start. On Shopify, Rendered Fits recommends a size for each product from your own size chart, so shoppers do not need a converter; there is a Free plan.
Sources: John Lewis international size charts, Charles Tyrwhitt formal shirt size guide (EU site), sizechart.uk men’s clothing size chart. Figures are taken from the tables in our clothing size converter, compiled on 29 September 2026. A value appears only where at least two published guides support it, and a dash means there is no consistent published figure.
Other size conversions
- UK to US women’s clothing sizes
- US to UK women’s clothing and jeans sizes
- EU and French to UK women’s sizes
- German to UK clothing sizes
- Italian to UK clothing sizes
- UK to EU men’s suits, trousers and shirts
- UK and US shoe sizes, both ways
- US to EU women’s sizes
- EU to US women’s sizes
- Australian to US women’s sizes
- EU to UK shoe sizes
- US to EU shoe sizes
- EU to UK men’s suit sizes
- EU to UK men’s trouser sizes
- US to UK men’s sizes
Every table in one place: the clothing size converter, or the size conversion guides index.
Frequently asked questions
What is a 15.5 collar in EU sizes?
A 15.5 inch collar is about 39.5 cm, printed as EU 39.
What is a 16 inch collar in EU sizes?
A 16 inch collar is about 40.5 cm, printed as EU 41 in our sources.
What is an EU 42 shirt in UK sizes?
An EU 42 shirt is a 16.5 inch collar in UK and US sizes.
What is an EU 38 shirt in UK sizes?
An EU 38 shirt is a 15 inch collar.
Are UK and US shirt collar sizes the same?
Yes. Both use the collar in inches, so a UK 15.5 is a US 15.5.
About Rendered Fits. Rendered Fits is a Shopify app for fashion brands that recommends a size for supported products from the brand's own size chart, and can show shoppers an optional AI try-on preview. There is a Free plan, and Complete is $349 a month with a 14-day trial.
Related: clothing size converter · what "true to size" means · size chart template