What is the formula for measuring Antenna range?

According to example 1 of this website

The formula for measuring the antenna range is this => D = radical(2hR)
which R is 6400km for earth and h is the height of our antenna from ground.

So if we have a tower that has 100 meter height,the maximum coverage range for this tower is about 35.77km.

My question is , what is the coverage range of the specific antenna? for example yaggi , horn , dipole , parabolic reflector with …
The formula above is just for the tower range, not for the antenna of specific frequency and gain.