This tool calculates the deciBel (dB) antenna gain from its linear value.

**Calculator**

- Enter either the linear value of Antenna gain relative to Isotropic or half-wave dipole
- The tool provides both the dBi and dBd values.

ðŸ”„ Antenna Gain dB to linear

**Formula**

**G _{dBi} = 10*Log_{10}(G_{i})**

**G _{dBd} = G_{dBi} – 2.15**

where

**G**is the dB gain relative to an isotropic antenna_{dBi}**G**is the dB gain relative to a half-wave dipole_{dBd}

**Background**

Antenna gain is a measure of how well an antenna can convert input power into radio waves headed in a specified direction, compared to a reference antenna. It is a key parameter in evaluating antenna performance because it directly affects the effective range and strength of the radio signal.

Antenna gain can either be specified as a linear or logarithmic quantity. As well the reference antenna is either an isotropic antenna or a half wave dipole.

Antenna Gain depends on its antenna factor and frequency of operation.

**Example Calculation**

A linear gain of 9 (for example) relative to an isotropic antenna gives

G_{dBd} = 7.39 and G_{dBi} = 9.54

Note G_{dBi} = 7.39 + 2.15