Tree Height and Slope Clinometer

Use your phone angle sensor or manual angle entry to estimate tree height and slope on site.

Everything stays in the browser, so it is useful offline and in remote field work.

Estimate height with eye-height or top-and-base methods Switch between meters and feet Save measurements on the device only

Safety notice

Do not move around while measuring on unstable ground or steep slopes.

First make sure the area is safe near roads, drop-offs, or falling-branch hazards.

If the sensor keeps drifting, hold the phone still before you save the angle.

How to use

Enter the horizontal distance to the tree. Do not use slope distance.
Choose the tree height method, then enter the top angle and either eye height or base angle.
If your device supports it, enable the angle sensor and capture the current reading into the inputs.
Review the result and save the measurement to the device if you want to reuse it later.

Sample

Formulas

H = D × tan(θ_top) + h_eye
H = D × (tan(θ_top) - tan(θ_base))
Grade% = tan(θ) × 100
1:n = 1 : (1 / |tan(θ)|)

Glossary

Horizontal distance

The distance measured on a level plane, not along the slope.

Eye height

The height from the ground to your eye or the phone sensor position.

Top angle

The upward angle toward the tree top. Positive above the horizon.

Base angle

The angle toward the tree base. Useful on sloped ground with signed values.

Clinometer

A tool class that measures angle and turns it into slope or height values.

FAQ

Does it work on phones without a sensor?

Yes. You can type the angles manually. The sensor is only an input helper.

Why use horizontal distance?

Because the tree-height formulas are based on horizontal distance and tan(angle).

How should I measure on sloped ground?

The top-and-base method is usually easier to keep consistent when the terrain is uneven.

Where are the measurements saved?

Only in this device's local storage. Nothing is sent to a server.

Why does iPhone permission not appear?

On iOS Safari, start from the enable button. If permission is unavailable, use manual input instead.

Notes

This tool is for estimates, not for official survey work or legal decisions.
Saved records stay on the device. Clear them after use on a shared device.
The eye-height method is simple, but the top-and-base method is often steadier on slopes.
Slope display depends on how steadily you hold the phone, so small jitter can change the reading.