EIRP Calculator
Calculate Effective Isotropic Radiated Power in dBm and Watts from transmit power, antenna gain, and cable losses.
Frequently Asked Questions
What is EIRP?
EIRP is the total power a theoretical isotropic antenna would need to emit to produce the same peak signal strength as the actual antenna in its main beam direction. It accounts for transmitter power, antenna gain, and transmission line losses.
What is the difference between EIRP and ERP?
EIRP is referenced to an isotropic antenna (0 dBi gain). ERP (Effective Radiated Power) is referenced to a half-wave dipole antenna, which has 2.15 dBi gain. EIRP(dBm) = ERP(dBm) + 2.15 dB. Regulators often specify limits in ERP.
What are typical EIRP limits?
Regulatory EIRP limits vary by country, frequency band, and application. For example, LTE macro base stations typically operate at up to 46 dBm EIRP. WiFi (2.4 GHz) is typically limited to 20 dBm (100 mW) EIRP in most regions.