The average male hand length is 189 millimeters, or 7.44 inches. Half of this distance is palm, and the other half is middle finger. So the length of the average male middle finger is 95 millimeters, or 3.72 inches.
The other fingers obviously have shorter lengths than that of the middle finger. It is also useful to know the average hand width, which is proportional to hand length. The average male palm width is 84 millimeters, or 3.3 inches. The female versions of these average dimensions are usually 90 percent of the male versions, making average hand length 172 millimeters, or 6.77 inches, and average palm width 74 millimeters, or 2.91 inches.