Here's How...
- Diameter is the width of a circle or cylinder; in this case the trunk of the tree.
- Tree trunks have taper (they are slightly cone-shaped), such that they are wider at the base and narrower further up.
- Thus, diameter will vary based on how high up on the trunk of the tree you measure it.
- A standardized height for measuring tree diameter has been established.
- This is known as breast height, which is defined as 4.5 feet (54 inches) above the ground, on the uphill side of the tree.
- Use a measuring tape to figure out how high up breast height is on you.
- Memorize this spot (e.g. the next to the top button on your shirt or coat) so that as you stand next to a tree, you know where to measure diameter.
- Measure the tree circumference (distance around) at 4.5 feet from the ground in centimeter units.
- Calculate the diameter of your tree using the following formula:
- Circumference ÷ pi (3.14) = Diameter
_________________ ÷ pi (3.14) = _____________________
circumference (include units) diameter (include units)