One wavelength is 300,000,000 (speed of light in metres/sec) / frequency in Hz.
Or for convenience use (300 / frequency in megahertz),
300 / 36 = 8.333 Metres wavelength.
How that applies to an antenna depends on the antenna type:
A quarter wave ground plane would be approx. 219cm; a quarter of the wavelength, * 0.95 "end correction", allowing for the lowering in frequency caused by the antennas own capacitance.
Got is Monopole is 12 inches I used a clip lead, I think it is working changed to 32 MC as it is slightly longer running 102.1 Aberdeen W.A. through an old EICO 324 . I hope the FCC does not send me a nasty letter !