Enter the original distance (ft), the original dose rate, and the required does rate into the Radiation Distance Calculator. The calculator will evaluate and display the Radiation Distance. 

Radiation Distance Formula

The following formula is used to calculate the Radiation Distance. 

Drad = SQRT( D1^2*R1/R2)

  • Where Drad is the Radiation Distance (ft)
  • D1 is the original distance (ft) 
  • R1 is the original dose rate 
  • R2 is the required does rate 

How to Calculate Radiation Distance?

The following example problems outline how to calculate Radiation Distance.

Example Problem #1

  1. First, determine the original distance (ft).
    • The original distance (ft) is calculated to be : 50.
  2. Next, determine the original dose rate. 
    • The original dose rate is measured to be: 6.
  3. Next, determine the required does rate. 
    • The required does rate is found to be: 2.
  4. Finally, calculate the Radiation Distance using the formula above: 

Drad = SQRT( D1^2*R1/R2)

The values given above are inserted into the equation below and the solution is calculated:

Drad = sqrt( 50^2*6/2) = 86.602 (ft)


Example Problem #2

The variables needed for this problem are provided below:

original distance (ft) = 100

original dose rate = 7

required does rate = 4

This example problem is a test of your knowledge on the subject. Use the calculator above to check your answer. 

Drad = SQRT( D1^2*R1/R2) = (ft)