Icon provides this chart which gives a recommended helmet size based upon a hat size or a head circumference measurement:
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| 1. Wrap flexible tape measure approximately 1 inch above eyebrows and ears |
| 2. Use this measurement to find your size on the chart to the below |
| Size | Hat Size | Measurement |
| XSmall | 6 5/8 – 6 1/2 | 20 7/8 – 21 1/4 |
| Small | 6 7/8 – 7 | 21 5/8 – 22 |
| Medium | 7 1/8 – 7 1/4 | 22 3/8 – 22 3/4 |
| Large | 7 3/8 – 7 1/2 | 23 1/3 – 23 1/2 |
| XLarge | 7 5/8 – 7 3/4 | 24 – 24 3/8 |
| XXLarge | 7 7/8 – 8 | 24 3/4 – 25 1/8 |
| 3XLarge | 8 1/8 – 8 1/4 | 25 1/2 – 26 |