Help me understand this
Feb 5, 2010 1:02 PM
Joined: Jan 23, 2010
Points: 64
24 ILD Latex
6” 32 ILD Latex
2” 40 ILD Latex
7/8” Firm foam


What do they mean? Thanks.
Re: Help me understand this
Reply #2 Feb 5, 2010 1:18 PM
Joined: Feb 2, 2010
Points: 88
Not to be confused with the similar IFD Rating which is used for poly foam (Indentation Force Deflection) The IFD refers to the firmness of a piece of foam. The lab puts a 4 x 15 x 15 inch piece of foam on a flat surface. A round metal plate, 8 inches in diameter pushes down on the foam. The amount of pounds of pressure it requires to squeeze the foam to 3 inches (25% compression) is referred to as IFD. A low IFD, such as 10, doesn’t offer much resistance and is considered soft. Generally speaking, an IFD of 15-24 is considered soft, 25-32 is medium, 33-40 is firm and 41+ is considered extra firm. The comfort range for the majority of people is 25-32.
This message was modified Feb 5, 2010 by Pete
Re: Help me understand this
Reply #3 Feb 5, 2010 1:19 PM
Joined: Feb 2, 2010
Points: 88
So basically ILD and IFD are the aneroid and mercury "firmness barometers". Two different testing methods to arrive at a common answer: the firmness of any given foam. A low IFD, such as 10, doesn’t offer much resistance and is considered soft. Generally speaking, an IFD of 15-24 is considered soft, 25-32 is medium, 33-40 is firm and 41+ is considered extra firm. The comfort range for the majority of people is 25-32.
This message was modified Feb 5, 2010 by Pete
Re: Help me understand this
Reply #4 Feb 5, 2010 6:05 PM
Joined: Aug 21, 2009
Points: 486
And I'm betting that would be too soft for you.  I have issues with low back and hip pain, and what I ended up with is a 100% latex mattress, nine inches of 36 ILD latex (extra firm) with a 2 inch convoluted latex topper of some softer ILD - maybe 24-28?

This firmness level allows a very supportive surface, which you back needs, with enough give to provide pressure relief in the hip and shoulder areas.

Sometimes I want a softer feel and move over to my husband's side of the bed, and he has 3 inches of firm latex (34 ILD) over six inches of extra firm latex (36 ILD) with the 2 inch convoluted topper over everything.  This is a bit too soft for my back, but every once in awhile I like the softer feel.