EIRP Calculator

EIRP calculator let you calculate the effective transmission power with a given combination of radio transmitter and antenna.

Equivalent isotropically radiated power (EIRP) or, alternatively, effective isotropically radiated power is the amount of power that a theoretical isotropic antenna (which evenly distributes power in all directions) would emit to produce the peak power density observed in the direction of maximum antenna gain. (from Wikipedia)