About this tool
The height meter tells you the height of trees, houses, poles or cliffs without climbing them. Your phone works as a clinometer: you sight the top, the tool measures the angle of elevation with the orientation sensor and computes the height with the tangent – just like a forester’s hypsometer.
If you know the distance, the angle to the top plus your phone’s height above the ground is enough. If you also sight the base, the phone height isn’t needed – which is more accurate on slopes, too. Without a distance, the tool derives it from the phone height and the angle to the base. Optionally the back camera with a crosshair serves as a sight. Surface tilt is measured by the Spirit Level, directions by the Compass.
How it works
- Stand far enough from the object to see the top without tilting much (about as far as it is tall) and enter the distance – or leave it at 0.
- Tap “Start sight”, hold the phone upright and sight the top over its top edge or through the camera. Tap “Capture top”.
- For more accuracy, sight the base and tap “Capture base”. The height appears right away.
Frequently asked questions
How accurate is measuring height with a phone?
The orientation sensor measures angles to about 0.5°. At 20 m distance, 0.5° corresponds to about 20 to 35 cm of height, depending on the angle. The biggest errors usually come from a poorly estimated distance and shaky sighting – rest the phone on something and measure several times.
Which formula is used?
Height = distance × tan(angle to top) + phone height. With both angles, height = distance × (tan(angle to top) − tan(angle to base)); the base angle is negative when you look down. Without a distance, it follows from phone height ÷ tan(−angle to base).
Why should I stand about as far away as the object is tall?
Around 45°, small angle errors matter least. Standing very close makes the angle steep and every tenth of a degree changes the result a lot; standing very far away makes the top hard to sight precisely.
Is the camera image stored?
No. The camera only serves as a viewfinder and is shown right in the browser; no pictures are taken or uploaded. You can also sight over the phone’s top edge without the camera.