Hat Size Converter
Hat sizes are based on head circumference measured around the head just above the ears. The United States and UK use numeric sizes in inches (6.5 to 7.75+ in increments of 0.125), while EU sizes are in centimetres. This reference table provides conversions between head circumference in centimetres and inches, plus US, UK, and EU hat sizes. Measure your head circumference with a soft tape measure and compare to this table.
Hat size conversion table
| Head Circ (cm) | Hat Size (in) | US/UK | EU |
|---|---|---|---|
| 52 | 6.5 | 6.5 | 52 |
| 53 | 6.625 | 6.625 | 53 |
| 54 | 6.75 | 6.75 | 54 |
| 55 | 6.875 | 6.875 | 55 |
| 56 | 7 | 7 | 56 |
| 57 | 7.125 | 7.125 | 57 |
| 58 | 7.25 | 7.25 | 58 |
| 59 | 7.375 | 7.375 | 59 |
| 60 | 7.5 | 7.5 | 60 |
| 61 | 7.625 | 7.625 | 61 |
| 62 | 7.75 | 7.75 | 62 |
How to measure your hat size
Measure your head circumference with a soft tape measure around the widest part, just above your ears. Record the measurement in centimetres or inches and refer to the table above. Hat sizes vary between brands, so try before purchasing when possible.
Notes
Hat sizes vary by brand and style. These are general guidelines. For fitted hats, consult brand-specific sizing guides.
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.