Path Loss in free space
UNITS: distance in meters
distance in km
distance in million km
distance in lightyears
Frequency: Input frequency
Gain TX antenna: Input gain TX antenna
Gain RX antenna: Input gain RX antenna
Path loss:

- Calculates the Path Loss (attenuation in dB) in a free field like space communications.
- Also the distance can be calculated if the Path Loss is given (in dB).
- Substract the field attenuation from the TX power in dBm to get the power in dBm at the RX input.
- Convert the TX power from watt to dBm and the RX power from dBm to uV with use of one of the calculators.
- The formula is: PATH LOSS(dB) = 32.44 + 20*log(F(MHz)) + 20*log(D(km)) - Gtx(dBi) - Grx(dBi).
- The antenna gain is in dBi. A dipole has a gain of 2.14 dBi.