Size Studio
55 cm Hat Size in US, UK and Letter Sizes
A 55 cm head is a US 6 7/8 and a UK 6 3/4 fitted hat, and usually S in letter sizes. That is about 21.6 inches around.
| Head (cm) | Head (in) | US | UK | Letter |
|---|---|---|---|---|
| 55 | 21.6 | 6 7/8 | 6 3/4 | S |
Good to know
- US fitted sizes are the head circumference in inches divided by π, in eighths. UK sizes run one eighth below US for the same head. EU sizes are the head in centimetres.
- Measure around your head just above the ears and eyebrows. Between sizes, choose the larger one.
Sizes either side
Smaller: 54 cmLarger: 56 cmOpen the full converterHow to measure yourself
Questions
What is a 55 cm head in US hat size?
US 6 7/8.
What size is a 6 7/8 hat in letters?
Usually S, but letter sizes vary by maker.
What is US 6 7/8 in UK hat size?
UK 6 3/4.
Shop Hats
More size tools
All tools- Shoe Size ConverterUS, UK, EU and cm for men and women, including men-to-women.
- Watch Size for Wrist CalculatorCase diameter, lug-to-lug and strap length for your wrist.
- Hat Size Chart & CalculatorHead measurement to US, UK, EU and S–XXL fedora sizes.
- Ring Size Converter & Printable SizerUS numbers, UK letters, EU, Japan and mm, plus a print-at-home sizer.
- Dress Size ConverterWomen's UK, US, EU, French, Italian, Australian and Japanese sizes.
- Jeans & Trousers Size ConverterWaist sizes to US, UK and EU for men and women.
- Belt Size CalculatorTrouser waist to belt size in inches and centimetres.
- Men's Shirt Size Chart (Neck & Sleeve)Neck size in inches and cm, S–XXL, and what 16/34 means.
- Backpack Size Guide (Litres)Dimensions to litres, and the right size for your trip.
- Men's Clothing Size ConverterSuits, jackets and T-shirts: UK, US, EU and chest sizes.