Tree Height Calculator

Related Calculators

Distance to tree: The ground distance from where you stand to the base of the trunk.

Angle to treetop: The angle from your eye level up to the top of the tree, measured in degrees.

Eye height: The height from the ground to your eyes, not to the top of your head.

Base adjustment: The extra amount added or subtracted when the tree base is below or above your eye level.

Reference height: The height of the person or stick used for the shadow comparison.

Reference shadow length: The shadow length of that same person or stick.

Height above your eyes: The vertical part from your eye level up to the treetop before any base adjustment is applied.

Simple range from measurement uncertainty: A rough low-to-high estimate based on the optional distance and angle uncertainty values.

Mistake: Entering Distance to tree (ft) in yards or steps instead of feet.
Fix: Use the exact unit shown in the label, or switch Units and re-enter the value in that system.

Mistake: Using Angle to treetop (degrees) as 0, 90, or a value extremely close to 90.
Fix: Enter an angle greater than 0 and less than 90. If the angle is very steep, move farther back and measure again.

Mistake: Choosing the wrong option for Where is the tree base relative to your eyes? .
Fix: Pick About level with my eyes , Below my eyes , or Above my eyes based on the ground at the base of the trunk, not the top of the tree.

Mistake: Typing Angle to tree base (degrees) even though the base is about level with your eyes.
Fix: Leave that advanced field blank unless the base is clearly above or below your eye level and you actually measured a separate base angle.

Mistake: Measuring Tree shadow length (ft) and Reference shadow length (ft) at different times.
Fix: Measure both shadows at the same time so the sun angle matches for the shadow method.

Mistake: Entering 0 for Reference shadow length (ft) or guessing the shadow tip.
Fix: Use a real shadow length greater than 0 and remeasure if the tip is blurry or hard to identify.

• The angle method assumes your Distance to tree is a horizontal ground distance to the tree base, not a straight-line sight distance.
• The shadow method works best when the tree and reference object are on roughly level ground and both shadows are measured at the same time.
• If the tree base is above or below your eyes and you do not enter Angle to tree base (degrees), the result uses the simpler base-position handling and may be less precise on slopes.
• Very steep Angle to treetop (degrees) readings, especially above about 75 degrees, can make small angle errors change the height a lot.
• The uncertainty output is a simple what-if range, not a formal confidence interval or survey-grade error analysis.
• Irregular treetops, hidden bases, leaning trees, and fuzzy shadow edges can make any field estimate differ from the true height.
• Unit switching assumes you re-enter or keep measurements in one consistent system from start to finish.

How the calculator works

For the angle method, the calculator first finds the vertical height from your eye level up to the treetop by using tangent. On level ground, that vertical part is added to your Eye height to get total tree height [1]. If the base is above or below your eye level on a slope, a separate base reading can be used to add or subtract the extra vertical part [3][4].

For the shadow method, the calculator uses a ratio: if a person or stick and the tree are lit by the same sun at the same time, the tree height scales with the shadow lengths.

Formulas used

height above eye level = distance to tree x tan(top angle x pi/180)

tree height on level ground = height above eye level + eye height

tree height when base is below eye level = top vertical + base vertical + eye height

tree height when base is above eye level = top vertical - base vertical

base vertical = distance to tree x tan(base angle x pi/180)

tree height by shadow = reference height x tree shadow length / reference shadow length

1 ft = 0.3048 m

Worked mini-example

Suppose you use the angle method with Distance to tree = 100 ft, Angle to treetop = 30 degrees, and Eye height = 5.5 ft on level ground. Then tan(30 degrees) is about 0.57735, so the height above your eyes is about 100 x 0.57735 = 57.74 ft. Add 5.5 ft, and the estimated tree height is about 63.24 ft.

For a shadow example, if Reference height = 5.5 ft, Tree shadow length = 40 ft, and Reference shadow length = 6 ft, then tree height = 5.5 x 40 / 6 = 36.67 ft.

Uncertainty range

If you enter Distance uncertainty (percent) and Angle uncertainty (degrees), the calculator recomputes a low and high estimate by decreasing and increasing the measured distance and top angle. This gives a practical sensitivity check, not a statistical confidence interval.

Assumptions behind the math

The angle method assumes the angle is measured from horizontal eye level, the distance is horizontal to the base, and the top and base of the tree are identified correctly. The shadow method assumes both shadows were measured at the same time on similar ground. Real trees can lean or have uneven tops, so field results are still estimates.