Under Armour size guide
How to Measure - Caps and Hats
HEAD SIZE: To find out which UA size to choose, measure your head size where you will be placing this hat. If you don't have a tape measure, use a string and measure it along a ruler. Compare this measurement with the UA hat size chart.
| Size | Head circumference (inches) |
|---|---|
| S/M | 207/8-211/2 |
| M/L | 22 - 23 |
| L/XL | 23 - 241/4 |
| XL/XXL | 241/4 -251/2 |