24 ILD Latex
6” 32 ILD Latex
2” 40 ILD Latex
7/8” Firm foam


What do they mean? Thanks.

They are describing the firmness of the foam. ILD---Indentation Load Deflection - A measure of the load-bearing capacity of foam. ILD is generally measured as the force (in pounds) required to compress a 50 square-inch circular indentor foot into a 4-inch thick foam sample no smaller than 24-inches square to a stated percentage of the foam's initial height. Common ILD values are generated at 75% of initial height. The greater the ILD, the firmer the foam.

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.

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.

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.