All knives are hand made, one at a time so no 2 are alike.  The size of the knife you choose has more to do with personal preference than anything else. 

As a general rule:

• Elk Skinner blades aveage approximalty 4 1/2 to 5 1/2 inches in lengeth.
• Bear Skinner blades aveage approximalty 4  to 4 1/4 inches in lengeth.
• Deer Skinner blades aveage approximalty 3 1/4 to 3 3/4 inches in lengeth.