If you cut down a tree and reveal the inner part of it, you will see a variety of light and dark rings in the wood. These rings can relay a wealth of information regarding the tree's growth conditions throughout its life. If you want to determine the age of a tree, count the rings. It's not a complicated process, yet you should know not to count every ring.
Collect a circle of wood from a tree that has been cut down or locate a stump of a tree that is not rotted.
Examine the wood for a circular pattern of light and dark rings. Each ring represents a layer of wood growth. The light rings represent spring growth and the dark rings represent summer growth. A tree acquires one light and one dark ring annually.
Count only the dark rings. Start from the middle and move outward toward one side. The number of dark rings equals the number of years the tree has been alive.