In good nutrition areas, even yearling bucks can have as many as 10 points. For a more exact guess of a deer's age, judge the inside spread, main beam length or base of its antlers. A buck at least 3 years old typically has an inside spread of 16 inches, a main beam length of 21 inches and an antler base 4 inches in diameter. Consider other factors when judging a deer's age. If the bases are larger than the eyes, the bases measure 3 inches in diameter or larger.
Specific measurements vary from region to region.
Body conformation is difficult to judge. You can usually recognize an older deer by its swayed back, long body, wide hams, long neck and long nose. The deer's head shape can also indicate its age. Also, compared to an older deer, a younger deer's neck is shorter in relation to its size. Visualize a box drawn from a standing deer's front hooves, up the legs to its back, across the back and down the back legs, then closing at its front hooves.