How to measure a tree: Height

Vertical height of the tree is measured to the nearest foot. The most reliable tools for this purpose are an Abney hand level, a hypsometer, or a transit. Lacking those, you can use a straight stick. Hold the stick at its base vertically at arm's length, making sure its length above your hand equals the distance from your hand to your eye. Walk backward away from the tree, staying approximately level with the tree's base. Stop when the stick above your hand appears to be the same length as the tree. You should be sighting over your hand to the base of the tree and, without moving anything but your eye, sighting over the top of the stick to the top of the tree. Measure how far you are from the tree, and that measurement - in feet - is the tree's height.

* Measuring tree height