Convert a frequency to its wavelength in metres, feet and inches, with the half and quarter wavelengths and the ham band.
Wavelength in metres = 299.792458 / frequency in MHz (the speed of light divided by frequency). This is the free-space figure; real antenna elements are a few percent shorter. The half and quarter wavelengths are the basis of dipole and vertical antenna lengths.
Wavelength in metres equals the speed of light (299.792458 million metres per second) divided by the frequency in hertz, which simplifies to 299.792458 divided by the frequency in MHz. So 14.2 MHz is about 21.1 metres, the 20m band.
Antenna elements have an end effect and travel slightly slower than free space, so a half-wave dipole is about 95 percent of a free-space half wavelength. That is why the dipole formula uses 468 rather than the free-space 492.
Ham bands are traditionally named by their approximate wavelength, such as 20m for around 14 MHz or 2m for around 146 MHz. The tool shows which named band a frequency falls in.