EIRP Calculator (Effective Isotropic Radiated Power)

Find EIRP from transmitter power, antenna gain and losses.

EIRP (dBm) 40

EIRP (W) 10

Formula: EIRP = Pt + Gain − Loss

Step-by-step with your numbers:

1. Values used:

2. Transmit power = 30 dBm

3. Antenna gain = 12 dBi

4. Cable/connector loss = 2 dB

6. EIRP = 40dBm

7. EIRP = 10W

Did we solve your problem today?

EIRP is the apparent power a perfectly isotropic antenna would need to match your directional system.

The math behind it

EIRP = transmit power + antenna gain − system losses, all in decibels. Convert dBm to watts with 10^((dBm−30)/10).

30 dBm + 12 dBi − 2 dB → 40 dBm = 10 W EIRP.

Why does it matter?

Regulators cap EIRP to limit interference and exposure.