Minecraft wiki entry for Measuring_distance, associated text: Pointing at the target, using FOV 30 or a spyglass for greatest accuracy, and the debug screen on, divide the difference in elevation by the tangent of the tilt angle. If you are on a high mountaintop at Y=137 and you see an Amethyst Geode in a swamp, you can estimate it is at sea level, or Y=63. The debug screen says you are at "XYZ: -743.349 / 137.0000 / 540.144" and two lines below that, you are looking at a target "Facing: north (toward negative Z) (-136.2 / 21.9)". Your tilt angle is 21.9° and your rotation is 360 - 136.2 = 223.8°, converting from Minecraft's -180°/+180° notation to conventional 0° to 360° notation. The elevation difference, ∆Y, is 137 - 63 = 74. Find the distance by dividing ∆Y by the tangent of the tilt angle: 74 ÷ tan (21.9) = 74 ÷ 0.402 = 184.08 blocks.