Enter the number of grating lines and the total length (mm) into the Grating Density Calculator. The calculator will evaluate and display the Grating Density. 

Grating Density Formula

The following formula is used to calculate the Grating Density. 

GD = GL / L

  • Where GD is the Grating Density (lines/mm)
  • GL is the number of grating lines 
  • L is the total length (mm) 

How to Calculate Grating Density?

The following example problems outline how to calculate Grating Density.

Example Problem #1:

  1. First, determine the number of grating lines. 
    1. The number of grating lines is given as: 100.
  2. Next, determine the total length (mm). 
    1. The total length (mm) is provided as: 25.
  3. Finally, calculate the Grating Density using the equation above: 

GD = GL / L

The values given above are inserted into the equation below:

GD = 100 / 25 = 4 (lines/mm)


Example Problem #2: 

For this problem, the variables needed are provided below:

number of grating lines = 85

total length (mm) = 93

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

GD = GL / L = ?