Size breakdown
8 1/8 hat size in cm and inches
A US 8 1/8 fitted hat is cut for a head that measures 25 3/8 inches around — 64.5 cm.
US fitted
8 1/8
circumference 25 3/8 in ÷ π
Head circumference
64.5 cm
= 25 3/8
UK size
8
= US minus 1/8
EU size
65
= cm rounded
Letter size: about XXL. XXL.A head measured up to 0.3 cm from 64.5 cm matches this size; between sizes, take the next size up for a non-adjustable hat.Letter sizes vary by brand; check the brand's own chart.
Where 8 1/8 sits on the hat sizes chart
This size and its neighbours, so you can compare at a glance:
| US | UK | Head (cm) | Head (inches) | EU | Letter |
|---|---|---|---|---|---|
| 8 hat size | 7 7/8 | 63.5 | 25 | 64 | XXL |
| 8 1/8 hat size | 8 | 64.5 | 25 3/8 | 65 | XXL |
| 8 1/4 hat size | 8 1/8 | 65.4 | 25 3/4 | 65 | XXL |
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