Hat size converter

Convert your head circumference in centimeters to the US, UK, and EU hat sizes commonly used by hatters. Simply measure your head circumference with a tape measure to get a reliable match, calculated locally in your browser.

Example:
Measure with a flexible tape measure, about 1 cm above your eyebrows and ears.

How it works

Buying a hat online, especially from an American or British site, often means converting your head circumference to a different sizing system than the one used in France. This tool is based on a standard correspondence table between head circumference in centimeters and US, UK, and EU sizes.

How do I correctly measure my head circumference?

Use a flexible (sewing) tape measure and wrap it around your head, about 1 centimeter above your eyebrows and ears, at the widest point of your skull. The tape should be horizontal and snug without being too tight. Repeat the measurement two or three times for more reliability.

What if my measurement falls between two sizes?

If your head circumference falls between two sizes in the table, it's generally advisable to choose the larger size, especially for hats made of rigid material (felt, straw) that don't adjust. Some models also offer an adjustable inner band that tolerates a small margin of error.

Your head circumference measurement stays private: no data is sent to a server.