Enter 3 of the following 4 values into the calculator; initial radiation intensity, final radiation intensity, initial distance, final distance. The calculator will solve for the missing value.

## Inverse Square Law Formula

The following formula is used to calculate the values in an inverse square law.

I1 / I2 = d2^2 / d1^2

- Where I1 is the initial radiation
- I2 is the final radiation
- D2 is the final distance
- D1 is the initial distance

## Inverse Square Law Definition

The inverse square law states that any physical quantity is proportional to the square of the distance from the source of the physical entity.

## Inverse Square Law Example

How to calculate the inverse square law?

**First, determine which variable is being solved for.**Determine which of the 4 variables above is missing.

**Next, determine the value of the other variables.**For example, if solving for initial radiation, this would be final radiation, final distance and initial distance.

**Finally, calculate the missing variable.**Calculate the missing value using the inverse square law equation.

## FAQ

**What is an inverse square law?**

The inverse square law states that any radiation is proportional to the square of the distances from the source of the radiation.