Fade Margin / System Operating Margin Calculator

Fade margin is the difference between the strength of the received signal at the antenna port and the minimum signal strength in dB, determined by the manufacturer for reliable operation. The higher the fade margin, the more reliable the link will be. The required Fade Margin depends on several factors including: Frequency used, link distance and reliability requirements.  For example, a 2.4GHz, ISM band radio usually requires a minimum of 15dB fade margin.  A 5GHz ISM / UNII band radio usually a minimum of 10dB.

** Please fill in the gray squares and then click the "Calculate" button.  Answers appear in red squares below **

MHz

Miles

Transmit Antenna Gain

dBm

dB

dBi

Receive Cable Loss

dBi

(dBm)

dBi

Free Space Loss

Receive Signal Level

Fade Margin in dB

dB

dBm

dB