This tool calculates the physical dimensions of a 40 meter dipole antenna.
At 40 meters, the dipole length (L) is 62.4 feet. The length of each element of the dipole (l) is half of that at 31.2 feet.
The total length (L) of the dipole antenna is calculated as:
L = 468 / f
where f is the frequency in MHz.
f is calculated from the wavelength. For 40m the frequency is 7.5 MHz.
The length of each arm of the dipole
l = L/2