Enter the oil film parameter and the combined surface roughness into the Oil Film Thickness Calculator. The calculator will evaluate the Oil Film Thickness. 

Oil Film Thickness Formula

The following two example problems outline the steps and information needed to calculate the Oil Film Thickness.

OFT = P * R


  • OFT is the Oil Film Thickness (mm)
  • P is the oil film parameter 
  • R is the combined surface roughness 

How to Calculate Oil Film Thickness?

The following steps outline how to calculate the Oil Film Thickness.

  1. First, determine the oil film parameter. 
  2. Next, determine the combined surface roughness. 
  3. Next, gather the formula from above = OFT = P * R.
  4. Finally, calculate the Oil Film Thickness.
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

oil film parameter = 30

combined surface roughness = 20

OFT = P * R = ?