**RF Power Conversion Calculator**

#### RF power can be presented in terms of watts or in terms of decibels. The decibel unit was invented because the human ear perceives sound intensity logarithmically. It is also much easier to calculate total gains or losses if the decibel unit is used. The watt is a much more convenient unit used by engineers when it is needed to know how much power an equipment is emitting or receiving.

#### As an RF signal propagates away from a transmitter the power density reduces conserving the power in the EM wave. In the absence of obstacles and without atmospheric attenuation the total power passing through the surface of a sphere centered on a transmitter is equal to the power transmitted. Since the area of the sphere of radius rr is 4πr24πr2, the power density, e.g. in W/m2W/m2, at a distance rr drops off as 1/r21/r2. With obstacles the EM wave can be further attenuated.

**Formula**

**Where**

**P**_{dBm}= Power in decibel milliwatts

_{dBm}= Power in decibel milliwatts

**P**_{dBW} = Power in decibel watts

_{dBW}= Power in decibel watts

**P**_{mW} = Power in milliwatts

_{mW}= Power in milliwatts

**Example**

**Example 1**

#### Let’s calculate power in decibel milliwatts by using RF power. Consider power in millivolts P_{m}W is 30 milliwatts.

#### Let’s apply formula

**P**_{dBm}=10log10P_{m}W

_{dBm}=10log10P

_{m}W

#### P_{dBm }= 10log10*30

**P**_{dBm } = 14.7712 dB_{m}

_{dBm }= 14.7712 dB

_{m}

#### Example 2

#### Let’s calculate power in decibel watts by using RF power. Consider power in watts P_{W }is 25.

#### Let’s apply formula

**P**_{dBW}=10log10P_{W}

_{dBW}=10log10P

_{W}

#### P_{dBW }= 10log10*25

**P**_{dBW} = 43.9794

_{dBW}= 43.9794

#### Example 3

#### Let’s calculate power in milliwatts by using RF power. Consider power in decibel milliwatts P_{dBm }= 25.

#### Let’s apply formula

#### P_{mW }=10

#### P_{mW }= 10

**P**_{mW} = 316.2278

_{mW}= 316.2278

#### Example 4

#### Let’s calculate power in watts by using RF power. Consider power in decibel watts P_{dBW }= 30.

#### Let’s apply formula

#### P_{W}=10

#### P_{W }= 10

**P**_{W }= 1e+300

_{W }= 1e+300