Work out free space path loss instantly with clear inputs, formula shown and shareable results.
Free space path loss is 32.44 + 20log10(d in km) + 20log10(f in MHz) dB. Both distance and frequency contribute 6 dB per doubling, so a 5 GHz link loses 6 dB more than a 2.4 GHz one over the same distance. Antenna gain at each end is subtracted from that loss.
Free space path loss
FSPL(dB) = 32.44 + 20 log10(d km) + 20 log10(f MHz)
The receiving antenna's effective aperture for a given gain shrinks with wavelength, so it intercepts less of the spreading wavefront.
Obstacles intruding into the first Fresnel zone cause diffraction loss. Clearing 60% of its radius is the usual planning requirement.