Gain of Antennas Calculation

The calculator will calculate the Antenna Gain for given values.

Efficiency (η)
Wave Length (λ)
Physical Aperture Area (A)
Antenna Gain(GdBi) =

This is to find the Antenna Gain for given values of efficiency, wave length, physical aperture area. The relative increase in radiation at the maximum point expressed as a value in dB above a standard is called antenna gain.


GdBi = 10 LOG10(η 4 πA / λ2)


η = Efficiency,

λ = Wave Length,

A = Physical Aperture Area.

The gain of an antenna

The antenna gain has no units because it the is a ratio and ability of the antenna to radiate less or more in any direction compared to a theoretical antenna. The isotropic antenna, theoretically can be made as a perfect sphere, it would radiate equally in all directions. Its maximum possible value would be realized in the ideal situation in which none of the energy supplied by the transmitter was wasted and all of it was concentrated within the optimum beam shape.