Examples Assuming no atmospheric refraction and a spherical Earth with radius R=: For an observer standing on the ground with h = , the horizon is at a distance of . For an observer standing on the ground with h = , the horizon is at a distance of . For an observer standing on a hill or tower above sea level, the horizon is at a distance of . For an observer standing on a hill or tower above sea level, the horizon is at a distance of . For an observer standing on the roof of the Burj Khalifa, from ground, and about above sea level, the horizon is at a distance of . For an observer atop Mount Everest ( in altitude), the horizon is at a distance of . For an observer aboard a commercial passenger plane flying at a typical altitude of , the horizon is at a distance of . For a U-2 pilot, whilst flying at its service ceiling , the horizon is at a distance of .
Examples Assuming no atmospheric refraction and a spherical Earth with radius R= For an observer standing on the ground with h =  the horizon is at a distance of  For an observer standing on the ground with h =  the horizon is at a distance of  For an observer standing on a hill or tower above sea level the horizon is at a distance of  For an observer standing on a hill or tower above sea level the horizon is at a distance of  For an observer standing on the roof of the Burj Khalifa from ground and about above sea level the horizon is at a distance of  For an observer atop Mount Everest ( in altitude) the horizon is at a distance of  For an observer aboard a commercial passenger plane flying at a typical altitude of  the horizon is at a distance of  For a U-2 pilot whilst flying at its service ceiling  the horizon is at a distance of 