This is the only way to know for certain how old a tree is, since all of the other methods are simply estimates. If possible, conduct research to find out when the tree might have been planted. Ask older residents of the neighborhood or look at old photographs to try to date the tree.






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, Some species of trees, such as particular conifers, produce annual branch whorls. Counting branch whorls can be used to estimate the tree's age. This method is not as accurate as cutting down the tree and counting the rings, but it's a way to estimate the tree's age without having to kill it.








Count the number of branch whorls above chest height.













Add 1 to your total to account for the tip of the tree.
 If you know the average annual width of tree ring for that species, you can multiply it by the diameter of the trunk to estimate the tree's age. Different species' growth factors are dependent on their environment - for example, forest trees grow faster than city trees - so this method for determining a tree's age is truly an estimate.

Measure the circumference of the trunk in inches. Use the trunk width at 4.5 feet (1.4 m) off the ground.
Calculate the diameter (circumference divided by pi).
Multiple the diameter and the tree species' average growth factor. This will give you the approximate age of the tree in years. You can figure out a tree's growth factor by searching online or measuring the rings of a dead tree from the same species.
Try to find out when it was planted.
Count the tree's whorls.
Multiply the diameter by the growth factor.A tree's growth factor is the measurement of the width it gains annually.
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