RF Power Density Calculator

Enter value and click on calculate. Result will be displayed.

Formula given below is as per EPA FCC OET Bulletin NO 65.
S = ( P × G ) / ( 4 × Pi × R2 )
S = Power Density
P = Power Input to Antenna
G = Power Gain of Antenna
R = Distance to center of Radiation of Antenna

Power Input to Antenna (P):
mW
Power Gain of Antenna (G):
Distance to center of Radiation of Antenna (R):
cm
Power Density (S):
mW/cm2

What is an RF Power Density Calculator?
An RF Power Density Calculator is a tool used to calculate the power per unit area of an RF (Radio Frequency) signal. It helps assess how much power is distributed over a given area, which is essential for understanding how radio waves interact with their environment (such as antennas, waveguides, or free space).

Why Use It?
Regulatory Compliance: Ensures RF emissions stay within legal power density limits (important for safety and communication standards).
Antenna Design: Helps in designing antennas to maximize the power delivered to a target area.
Optimizing RF Power: Ensures efficient power usage in communication systems to reduce interference and improve signal quality.
Health and Safety: Determines RF exposure to prevent harmful levels of radiation.
How Does It Work?
The calculation typically involves the following formula:


​
Where:

Power Output (P) is the total RF power (in watts, W) emitted by the antenna or source.
Area (A) is the area over which the power is distributed, typically measured in square meters (m²).
For a spherical distribution around an antenna, the area can be calculated using the surface area of a sphere:



Where:

r is the distance from the antenna (in meters).
So, the power density at a distance r from the antenna becomes:

When to Use It?
Designing communication systems (e.g., cell towers, satellite links).
Evaluating electromagnetic field (EMF) exposure in wireless environments.
Testing antennas and assessing radiation patterns.
Verifying compliance with RF exposure limits, especially in workplace environments.
Optimizing wireless networks for better coverage and signal strength.