Interstellar Communication Range Calculator

How far could a radio signal travel between two civilizations — and still be detected?

Interstellar radio communication is fundamentally a question of signal strength, distance and technology. A transmission becomes weaker as it travels through space, while the ability to detect it depends on the capabilities of both the transmitting and receiving systems.

This calculator lets you explore that relationship. Adjust the parameters of the radio link below to estimate the distance over which a signal could be detected and compare how different transmitter, antenna, receiver and signal configurations affect the result.

Try changing the parameters and see how far an interstellar radio link could reach.

The calculator provides a theoretical engineering estimate based on the selected assumptions. It does not represent the probability of detecting an extraterrestrial civilization.