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

The inverse square law shows that the quantity of radiation is proportional to the distance from the source.

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?

  1. First, determine which variable is being solved for.

    Determine which of the 4 variables above is missing.

  2. 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.

  3. 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.