| Size | Between Eyes | Top To Bottom | Cheek Bone Circumference | Approx. Horse Size | |
| XS | IN | 3 | 13 | 18 | Ponies, Weanlings |
| CM | 7.6 | 33.0 | 45.7 | ||
| S | IN | 3 | 13.5 | 20 | Ponies, Yearlings, Morgans, Arabians |
| CM | 7.6 | 34.3 | 50.8 | ||
| M | IN | 4.75 | 15 | 21 | Refined Quarter Horses, Small Thoroughbreds |
| CM | 12.1 | 38.1 | 53.3 | ||
| L | IN | 5 | 16 | 23 | Thoroughbreds, Standardbreds |
| CM | 12.7 | 40.6 | 58.4 | ||
| XL | IN | 5.5 | 17 | 24 | Larger Heads, Warmbloods |
| CM | 14.0 | 43.2 | 61.0 | ||
*Measurements are approximate as masks are hand made in the USA. A tight, compression-type fit is not necessary for effectiveness.