How to Measure Tree Weight

Measure the large diameter of the tree with a tape measure. Assume the large diameter in this example is 3 feet. Divide the large diameter by 2 to get the large radius. The large radius of the tree in this example is therefore 3 / 2 = 1.5 feet.

Measure the small diameter of the tree with a tape measure. Assume the small diameter in this example is 1 foot. Divide the small diameter by 2 to get the small radius. The small radius of the tree in this example is therefore 1 / 2 = 0.5 feet.

Measure the length of the tree from one end to the other with a tape measure. Assume the length of the tree in this example is 92 feet.

Calculate the volume of the tree with the formula V = Pi x L / 3 x (R^2 + (R x r) + r^2). Pi is a constant, L is the length of the tree, R is the large radius of the tree and r is the small radius of the tree. Pi is about 3.142, L is 92 feet, R is 1.5 and r is 0.5 in this example. The volume of the tree is therefore V = Pi x L / 3 x (R^2 + (R x r) + r^2) = 3.142 x 92 / 3 x (1.5^2 + (1.5 x 0.5) + 0.5^2) = 313.2 cubic feet.

Multiply the volume of the tree in cubic feet by the density of the wood in pounds per cubic feet to get the weight of the tree in pounds. Assume for this example that the tree is Oregon Pine with a density of 33 pounds per cubic foot. The weight of the tree in this example is therefore 313.2 x 33 = 10,336 pounds.