Visual Horizon

The visible horizon is based on the curved Earth and a straight line of sight. This calculator uses Earth radius at the selected latitude and computes the horizon arc distance for both transmitter and receiver.

Secant Trigonometry
Secant Trigonometry

Horizon Calculator

Enter transmitter and receiver heights above sea level. Typical HT heights are about 1.5 m (5 ft).

Heights are entered in feet or meters.
deg
Used to calculate Earth radius from the WGS84 ellipsoid.
ft
Displayed in the selected height unit.
ft
Height of the transmitter antenna above sea level.
ft
Height of the receiver antenna above sea level.

Results

mi / km
mi / km
mi / km