Instructions
Look at the man's hair. The average man begins to gray at about age 30. Men can begin to gray sooner, and some men have a full head of dark hair into their 50s, but looking at hair is a good place to start. Keep in mind that a man may cover his gray spots, so look at the roots for a more accurate idea.
Look at his face. Wrinkles are one of the most foolproof signs of aging. Men in their 20s and 30s tend to have supple, smooth skin, whereas men in their 40s, 50s and beyond begin to display increasing wrinkles. Common areas for wrinkles include around the mouth and across the forehead. Men who spend long hours outdoors may have wrinkles that cause them to look beyond their years.
Look at the man's physical stature. Men tend to put on weight when they get older. This indicator should not be used by itself but instead combined with other tricks to determine a man's age. As a man ages, his metabolism slows down, causing him to gain weight unless he alters other behaviors, such as eating and exercise.