# Friis Transmission Equation Calculator

In telecommunications engineering, Friis Transmission Equation is used to measure the power received by one antenna with idealized conditions, while other antenna was kept some distance away transmitting the known amount of power. It determines the free space path loss, antenna gains & wavelength to the received & transmitted powers.

Calculate the received power using the transmitter power and gain, distance & frequency with this Friis transmission equation calculator.

In telecommunications engineering, Friis Transmission Equation is used to measure the power received by one antenna with idealized conditions, while other antenna was kept some distance away transmitting the known amount of power. It determines the free space path loss, antenna gains & wavelength to the received & transmitted powers.

Calculate the received power using the transmitter power and gain, distance & frequency with this Friis transmission equation calculator.

Code to add this calci to your website

#### Formula:

P_{r}=P_{t} × G_{t} × G_{r} × (c/(4 × π × d× f))^{2}
P(dB)_{r}=P_{t} + G_{t} + G_{r} + (20 × log(c/(4 × π × d × f)))
**Where,**
P_{r} = Received Power
P_{t} = Transmitter Power
G_{t} = Transmitter Gain
G_{r} = Receiver Gain
d = Distance
f = Frequency
P(dB)_{r} = Received Power in dB
c = Speed of light (equal to 3 ×10^{8 }m/s)
### Example

Find the received power if the frequency, transmitter power, transmitter gain and receiver gain values are 25Hz, 23dBm, 11dB, 12dB and the distance between 6 meters.

#### Friis Transmission Equation Calculation

P_{x} = 23 x 11 x 12 x (299 792 458 / (4 x 3.14 x 6 x 25))

= 150.0329 dBm