Hat Size Converter
Convert head circumference to approximate US/UK fitted hat size and international size.
How to Use the Hat Size Converter
Measure around the widest part of your head, usually just above the eyebrows and ears, then use the converter to compare common US, UK and EU hat sizes.
Practical Example
A head circumference of about 58 cm often corresponds to an EU size 58 and roughly a US hat size around 7 1/4, depending on the sizing chart.
Factors That Affect Fit
Brand sizing, hat style, material, lining and personal fit preference can change the best size. Structured hats may fit differently from stretch or knit styles.
Frequently Asked Questions
Where should I measure my head?
Measure around the fullest part, just above the eyebrows and ears.
Should I round up between sizes?
Usually yes if you prefer a more comfortable fit, but check the brand chart.
Do hat sizes vary by country?
Yes. Different markets use numeric, fractional or centimeter-based sizing.
Understanding Hat Size Conversion
Hat sizes are based primarily on head circumference, but sizing systems differ between regions and manufacturers. Converting a measured circumference to US, UK or EU sizing provides a useful starting point when shopping across different brands. The closest listed size is usually preferable to relying only on a generic small, medium or large label.
Measure around the widest part of the head, typically just above the eyebrows and ears, keeping the tape level without pulling it too tight. If the measurement falls between sizes, choosing the larger option is often more comfortable unless the hat material is designed to stretch. Always compare the converted result with the specific brand chart when available.
Conversion Details and Practical Limits
Temperature scales do not convert with a simple multiplier because Celsius and Fahrenheit have different zero points. Kelvin is an absolute thermodynamic scale, and physically meaningful Kelvin values cannot fall below absolute zero.