Link Budget Calculator

This calculator can help you determine the antennas and power needed to make a line-of-sight radio link. It does not take in account factors such as fresnel zones, noise levels, and obstructions in the radio path. Also, make sure you take in account fade magin! Sometimes, signals can fluxuate over time due to trees, temporary obstructions and atmospheric conditions. Be sure to leave a few dB to spare, depending on the reliability you seek.


Frequency (MHz):

Distance (Kilometers):

Transmitting Station

Transmitter Power (dBm):

Transmitter Coax and Misc. Losses (dB):

Transmitter Antenna Gain (dB):

Receive Station

Receiver Antenna Gain (dB):

Receiver Coax and Misc. Losses (dB):

Receive Strength Result:

You will want a few dB in your fade margin. If this number is negative, communication may not be possible, no matter what the circumstances.

LoRa Fade Margin:

GMSK Fade Margin:

FM Audio Fade Margin: