Convert hat sizes between US, UK, European (cm) and head circumference.
Apparel • US/UK/EU
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Hat sizes vary by country: the US and UK use fractional numbers, while Europe uses head circumference in centimeters. This chart converts between US, UK, EU and your head measurement.
Measure around your head just above the ears and eyebrows; that circumference in centimeters is your EU size and maps directly to the US and UK sizes shown here.