Radio or Light Power at Distance Calculator

This tool can be used to calculate the Electromagnetic Radiation (EMR), radio or light power intensity received from an omnidirectional source, based on a given source power level, at a large distance from the source. It uses the standard inverse square formula for electromagnetic radiation intensity, that moves outwards from the source in spherical shape.

It can be used to calculate theoretical radio power intensity at distances in AU (Astronomical units) or light years from a source. It can also be used to calculate the light intensity or available solar power in space available per meter, from a given star at a distance away from the star.

Note that the Sun's power at source is 3.828e26 watts (3.828e26 means 3.828 X 10^26) which can be used in this calculator to determine solar power in space at a distance from the sun. At 1 AU, this power level is 1361.16 Watts per square meter in space, which would be available to a space station. On Earth there is less solar power than in space at a given distance from the sun, due to losses as the sunlight passes through the atmosphere.

The tool also can will calculate the time that the light or radio signal would take to travel in a vacuum (at the speed of light) from the source.

The output is also given in watts per square meter, as well as in decibel watts per square meter.

The Power Formula used in this calculator is: I = P / (4 * π * r * r) where P is the power in watts, and r is the distance in meters, and I is the intensity in watts per square meter.