How to calculate the height of a tree

h = height of survey observer (to eye level)

Above: Measuring the height of a mature tree. Where a tree is too tall for its height to be measured directly, it can easily be calculated using simple trigonometry. The survey recorder stands at a measured distance from the base of the tree (baseline B). Using a hand-held device called a clinometer, he or she measures the angle in degrees between the horizontal, their eye and the top of the tree (the angle bpt = angle A). Then, using tangent tables (obtained from trigonometrical tables or from a calculator) and the equation Height of Tree = h + B x tan(A), the survey recorder can calculate the height of the tree and record it in a table.