[{"data":1,"prerenderedAt":24},["ShallowReactive",2],{"content-height-meter-en":3},{"about":4,"steps":7,"faq":11},[5,6],"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]].",[8,9,10],"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.",[12,15,18,21],{"q":13,"a":14},"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.",{"q":16,"a":17},"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).",{"q":19,"a":20},"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.",{"q":22,"a":23},"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.",1793808250313]