Enter the quantity of light emitted (lumens) and the light intensity (lumen/m^2) into the Optical Distance Calculator. The calculator will evaluate and display the Optical Distance. 

Optical Distance Formula

The following formula is used to calculate the Optical Distance. 

D = SQRT (Q / E)
  • Where D is the Optical Distance (m)
  • Q is the quantity of light emitted (lumens) 
  • E is the light intensity (lumen/m^2) 

To calculate optical distance from lumens, take the square root of the quantity of light divided by the light intensity.

How to Calculate Optical Distance?

The following example problems outline how to calculate Optical Distance.

Example Problem #1:

  1. First, determine the quantity of light emitted (lumens). 
    • The quantity of light emitted (lumens) is given as: 50.
  2. Next, determine the light intensity (lumen/m^2). 
    • The light intensity (lumen/m^2) is provided as: 20.
  3. Finally, calculate the Optical Distance using the equation above: 

D = SQRT (Q / E)

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

D = SQRT (50 / 20) = 1.581 (m)


Example Problem #2: 

For this problem, the variables needed are provided below:

quantity of light emitted (lumens) = 70

light intensity (lumen/m^2) = 50

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

D = SQRT (Q / E) = ?