Terrier mixes have an incredible range of sizes, depending on the terrier breed and with which other breed it is mixed. Terriers range from the diminutive Yorkshire terrier to the relatively massive black Russian terrier, which can stand up to 30 inches tall at the shoulders.
The exact size of a terrier mix depends on its parents, nutrition and genetics. One of the largest hybrid breeds recognized by the American Canine Hybrid Club (ACHC) is the Irish schnauzer, which is a cross between a giant schnauzer and an Irish wolfhound. It is frequently taller than 30 inches and heavier than 100 pounds. One of the smallest is the ratshire terrier, a cross between a Yorkshire terrier and American rat terrier, which is generally under 10 inches tall and weighs about 10 pounds.