Biltmore stick

The Biltmore stick is a tool used by foresters to estimate tree trunk diameter at breast height.

With practice a Biltmore stick is considered to be exceptionally accurate, often within half an inch on diameters.

On the other end of the spectrum, some foresters consider the use of a Biltmore stick to be no more accurate than their own visual estimates (based on experience estimating the height and DBH of trees), and make it practice for their surveys to be largely completed in this manner.

Diameter at breast height (DBH) is measured by holding the stick a fixed distance, usually 25 inches (64 cm), from the eye, and at breast height, which in the United States is 4.5 feet (1.4 m) up the bole of the tree.

To measure height, the user stands a fixed distance from the tree, usually 66 feet (20 m) in the United States.