Enter the power and radius into the calculator to determine the intensity of a wave.

## Intensity Formula

The following formula is used to calculate the intensity of a wave.

I = P / (4*pi*r^2)

- Where I is the intensity (W/m^2)
- P is the power (W)
- r is the radius (m)

To calculate intensity, divide the power by 4 times pi times the radius squared.

## Intensity Definition

Intensity is defined as the power per unit area contained by a wave.

## Intensity Example

How to calculate intensity?

**First, determine the power of the wave.**For this example, the power of the wave is found to be 200 W.

**Next, determine the radius of the wave.**The radius of the wave is found to be .5m.

**Finally, calculate the intensity.**Using the formula we find the intensity to be 200 / (4*pi*.5^2) = 63.66 W/m^2

## FAQ

**What is an intensity?**

In physics, intensity is used to describe the power per unit area carried by a wave.