Tree Height Calculator
Measure tree height using trigonometry or shadow methods. Free online tree height estimator with trigonometric angle formulas and similar-triangles shadow calculations.
Angle from eye level to the base of the tree (positive value). For trees above viewpoint, the base is above eye level.
About This Calculator
The Tree Height Calculator helps you measure the height of a tree without climbing it or using specialized equipment. Whether you are a landscaper, arborist, forestry student, or homeowner planning a treehouse, this calculator gives you quick and reliable height estimates using two proven methods.
The trigonometric method uses the tangent function and angles measured from your viewpoint. By entering the distance from the tree, the angle to the treetop (β), and the angle to the tree base (α), the calculator applies the formula tree height = (tan(β) ± tan(α)) × distance depending on the tree position relative to your viewpoint. The shadow method uses similar triangles: the ratio of your height to your shadow matches the ratio of tree height to its shadow, giving tree height = (your height × tree shadow) ÷ your shadow.
Regional Notes
India (IN): Common tree species include neem, banyan, peepal, and mango. Use meters for distance and height measurements as per IS standards. Forestry professionals often use the trigonometric method with a clinometer for accurate readings in plantations and urban forestry.
United States (US): Forestry professionals commonly use feet and the stick method or clinometer-based angle measurements. The shadow method works well for backyard trees. US Forest Service uses diameter-based allometric equations for precise biomass estimation.
United Kingdom (UK): Arborists often use the trigonometric method with a laser rangefinder and clinometer (hypsometer). The shadow method is popular for quick estimates in parks and gardens. UK standard units are meters for official records.
Frequently Asked Questions
How does the tree height calculator work?
The calculator offers two methods. The trigonometric method uses the angle to the treetop (β), angle to the tree base (α), and distance from the tree to compute height using the tangent function. The shadow method uses your height, your shadow length, and the tree's shadow length with similar triangles to estimate the tree height.
What is the formula for measuring tree height with trigonometry?
For trees at the same level or below the viewpoint: tree height = (tan(β) + tan(α)) × distance. For trees above the viewpoint: tree height = (tan(β) − tan(α)) × distance, where β is the angle to the treetop and α is the angle to the tree base, both measured from eye level.
How accurate is the shadow method for measuring tree height?
The shadow method (tree height = your height × tree shadow ÷ your shadow) is accurate when the tree and the person are on level ground and both shadows are measured at the same time. Accuracy can be affected by uneven ground, tree lean, or inconsistent shadow edges.
What tools do I need to use the trigonometry method?
You need a way to measure distance (tape measure, rangefinder) and a way to measure angles. Most smartphones have free clinometer or angle-measuring apps. You can also use a protractor with a weighted string as a simple clinometer.
Can I use this calculator for things other than trees?
Yes, the same trigonometric method works for measuring the height of buildings, flagpoles, towers, and other tall objects. The angle and distance approach applies to any vertical structure you can view from a distance.
What units should I use for measurements?
Use any consistent unit for all linear measurements (feet, meters, inches, etc.). Angles must be entered in degrees. The result will be in the same linear unit you used for distance (trig method) or heights and shadows (shadow method).
How does tree position affect the calculation?
For same-level and below-viewpoint trees, the angles to the top and base both contribute positively to the total height. For above-viewpoint trees (tree base above eye level), the angle to the base is subtracted because it represents height below the treetop but above eye level.
Is this calculator free to use?
Yes, the Tree Height Calculator is completely free to use with no registration required. You can share results via URL which saves your input values.