Hat Size Converter

How Hat Size Conversion Works

Hat sizes are based on the circumference of your head. Different countries developed their own numbering systems, but they all measure the same physical property. Our converter maps between these systems using standardized measurements.

The most universal measurement is head circumference in centimeters. If you can measure your head circumference, you can find your size in any system using our converter above.

Common Conversions

Important Notes

• •Conversions are approximate. Manufacturing tolerances mean slight variations between brands.
• •Hat shapes vary. A hat that fits in one style may feel different in another, even at the same size.
• •For the most accurate fit, always measure your head and compare to the manufacturer's size chart.