Size Guide

To choose the best fit, compare your measurements with Whistles sizing. For further guidance, view the full Size guide.

Size Conversion Chart - Hats
UK S/M M/L
US 5.5 6.5
EU 36 37
Australia 4 5
Japan 22 23
Size Conversion Chart - Hats
UK S M L
Head circumference cm 54-55 56-57 58-59
US 5.5 6.5 7.5
EU 36 37 38
Australia 4 5 6
Japan 22 23 24
Size Conversion Chart - Hats
UK XS S M L
cm 13-14 14-16 16.5-19 19-21
inches 5-5.5 6.5-7.5 7.5-8.5 8.5-9.5