Enter the thickness (in) and the maximum thermal conductivity (Btu-in/h-ft^2-F) into the Calculator. The calculator will evaluate the Max R-Value. 

Max R-Value Formula

R = T / MTC


  • R is the Max R-Value ()
  • T is the thickness (in)
  • MTC is the maximum thermal conductivity (Btu-in/h-ft^2-F)

To calculate Max R-Value, divide the thickness by the maximum thermal conductivity.

How to Calculate Max R-Value?

The following steps outline how to calculate the Max R-Value.

  1. First, determine the thickness (in). 
  2. Next, determine the maximum thermal conductivity (Btu-in/h-ft^2-F). 
  3. Next, gather the formula from above = R = T / MTC.
  4. Finally, calculate the Max R-Value.
  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.

thickness (in) = 378

maximum thermal conductivity (Btu-in/h-ft^2-F) = 4.123