Biology
Measure tree height from your distance to the trunk and the angle to the top.
Your inputs
Change any value — everything updates instantly.
Walk away on level ground and measure back to the trunk.
Read with a clinometer or phone app.
Height of your eyes above the ground.
Try an example
Tree height
47 ft
This means the tree is about 47 ft (14.3 m) tall.
What you are seeing
The dashed line is your sight line to the treetop.
You stand 50 ft away with eyes 5 ft up.
The tree works out at 47 ft tall.
Above eye level
42 ft
Distance × tan(angle).
Metres
14.31 m
Total height in metric.
Result explanation: Measured height
47 ft tall.
Real-life comparison: A 1° error changes the result by about 1.5 ft.
Low, normal or high? A good measuring angle.
Height against sight angle
How to read this chart: Height climbs faster at steep angles, which is why 30–45° is best.
Uses the tangent of the sight angle to find height above your eyes, then adds eye height.
About 47 ft tall.
Best on level ground with a clear view of the top.
Stand roughly one tree-height away for a 45° angle.
Distance times tangent of the angle, plus eye height.
H = d × tan(θ) + eye height
Symbols
Why this formula works
Right-triangle trigonometry: opposite = adjacent × tan(angle).
Unit check
ft × number + ft = ft ✓
Worked example
Common mistakes
The tree is about 47 ft tall.
Many free phone apps measure angle, or use the stick method.
Measure angles to the top and base separately; this tool assumes level ground.
Measure from the side the tree leans across, not toward you.
About the tree's height away, giving an angle near 45°.
Important limitation. Hidden tops and leaning trunks lower accuracy.
Tell us if a formula, unit, explanation, or result needs attention. Your message will include this calculator’s name and page.
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