Friis Transmission Calculator

Fairview Microwave's Friis Transmission Equation Calculator will calculate the received power from an antenna at some distance given a transmission frequency and antenna gains.

Note: Equation 1 below uses linear power units (mW/W), while Equation 2 uses dBm/dBW.

Calculation

Transmitter Power:

Transmitter Gain (dBi):

Frequency:

Distance:

Receiver Gain (dBi):

Result:

Received Power:

Friis Equation is used to find the ideal power received at an antenna from basic information about the transmission. The only inherent pitfall of Friis equation is the fact that it is only calculated for a single frequency, where transmissions are typically comprised of many. However, given a high enough center frequency, the difference in received power over the bandwidth should be reasonably small.

**Note: Like our Friis transmission equation calculator, all of our RF calculators allow SI prefix input. For example, if you wish to input "25000000", just type "25M" instead. See the quick-reference table below for all compatible SI prefixes.

Prefix	Symbol	Value
Tera	'T'	10¹²
Giga	'G'	10⁹
Mega	'M'	10⁶
kilo	'k'	10³

Prefix	Symbol	Value
pico	'p'	10^-12
nano	'n'	10^-9
micro	'u'	10^-6
milli	'm'	10^-3

Friis Transmission Calculator

Calculation

Result:

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