A half-wave dipole antenna is comprised of two quarter-wavelength conductors placed end to end .
Use this calculator to determine the length of a half wave dipole from the frequency. Enter either the wavelength and the tool will compute the antenna length (L).
At a wavelength of 10 meters, the frequency of operation is 30 MHz. The dipole length (L) is 15.61 feet or 4.76 meters.
The total length (L) of the dipole antenna is calculated as:
L = 468 / f
where f is the frequency in MHz.
The length of each arm of the dipole
l = L/2
 Dipole Antenna on Wikipedia