Measuring Tree Diameter Using a Tree Scale Stick

One measurement that can be taken with a Biltmore or tree scale stick is diameter. To measure diameter, first establish the point to be measured on the tree. This point will be diameter at breast height (DBH), which is 4.5 feet above the ground. Find the “Diameter of tree (inches)” side of the stick (Fig. 1). Stand facing the center of the tree and hold the stick horizontally at arms length so you can see the measurement increment. Line up the zero end of the stick with the left side of the trunk of the tree and look (do not move your head) to the point where the right side of the trunk meets the stick (Fig. 2).

Figure 1. The diameter measurement on a tree scale stick.

Figure 2. Displaying proper techniques of measuring diameter with a tree scale stick.

To account for the tree not being round, take a second measurement 90° to the first and average the two. When on sloping ground, always measure on the uphill side of the tree. Diameter is usually measured to the nearest inch, but if many trees are being measured, 2 inch classes are used.