Mensa Smart Pup Hat Size Chart
| XS | SM | MD | LG | XL | |
| Bill Width | 4.5" | 5.25" | 5.9" | 6.4" | 7" |
| Head Width | 3.5" to 4.25" | 4" to 5" | 4.5" to 5.75" | 5.5" to 6.25" | 6" to 6.75" |
| Neck Size | 12" to 15" | 14" to 16" | 15" to 18" | 17" to 21" | 20" to 25" |
| Approx. Weight | 13 to 25 lbs. | 22 to 45 lbs. | 40 to 65 lbs. | 60 to 100 lbs. | 100 to 150 lbs. |