Adult Impact Sizing Chart: Vapor, Charger, Velocity
| Impact Racing Size: | Small | Medium | Large | X-Large |
| Hat Size Equivalent | 6-7/8 to 7 | 7-1/8 to 7-1/4 | 7-3/8 to 7-1/2 | 7-5/8 to 7-3/4 |
| Inch Size Equivalent: | 21-5/8 to 22 | 22-1/2 to 22-3/4 | 23-1/4 to 23-5/8 | 24 to 24-1/2 |
| CM Size Eqivalent: | 55 to 56 | 57 to 58 | 59 to 60 | 61 to 62 |
Youth Impact Sizing Chart: Lil' Champ
| Impact Racing Size: | Small, Two Inserts | Medium, One Insert | Large, No Inserts |
| Hat Size Equivalent | 6-1/8 to 6-1/4 | 6-3/8 to 6-1/2 | 6-5/8 to 6-3/4 |
| Inch Size Equivalent: | 19 to 19-1/4 | 19-1/2 to 20 | 20-1/2 to 21 |
| CM Size Eqivalent: | 49 to 50 | 51 to 52 | 53 to 54 |