Depending on your elevation above sea levelâ€”and assuming no objects such as mountains are obscuring your view and the sky is perfectly clearâ€”the horizon appears at different distances. To calculate how far the visible horizon is, first measure the distance between the ground and your eye level. Add to this the measurement of how high your elevation is. If your total is in feet, multiply by 1.5 and then take the square root of the result (which will be in miles); if you used meters as your measuring unit, multiply by 13 and then take the square root (the result will be in kilometers).