Trying to understand ILD numbers for Latex

I think I have made the decision to go with a latex topped mattress and have narrowed it down to the #BestMattressEver and the Love Bed from Nest. I am coming from Memory Foam which I like in some ways but dislike the heat aspect and the lack of response underneath.

If I understand correctly the general principals of ILD would mean that assuming the same type of Latex is used a person who weighs 210lbs would have a similar amount of support on 28ILD as a 140lbs person on 19ILD. Is that right?

Basically I am trying to figure out if going with a soft option to better emulate the pressure relief properties of memory foam is the right way to go as at 140lbs I would imagine my experience on the soft model won’t be too far off from a 200lbs person on the medium if that makes sense.

Hi zexpress,

Note: there is a lot of information in this reply and if it’s more than you wish to read then the last two paragraphs are the two that are most important :slight_smile:

ILD stands for Indentation Load Deflection and with latex it’s a measure of how much force it takes for a 50 sq in compressor head to sink into a 6" core by 1.5". Higher ILD’s are firmer than lower ILD’s.

You are the only one that can feel what you feel on a mattress and even people with similar body types can still have very needs and preferences in a mattress and there are too many unknowns, variables, and individual preferences and sensitivities involved to be able to use a formula or for anyone to be able to predict how a specific mattress will feel to you or to make a specific suggestion or recommendation about which mattress or combination of materials and components would be the best “match” for you in terms of PPP (Posture and alignment, Pressure relief, and Personal preferences) based on specs (either yours or a mattress) or “theory at a distance” that can possibly be more accurate than your own careful testing or personal sleeping experience (see mattress firmness/comfort levels in post #2 here).

The relationship between firmness and support or alignment is also often misunderstood and many people believe that firmer is “more supportive” which isn’t always the case. A mattress that is too firm for a particular body type and sleeping position will provide poor support under the more recessed parts of the body and a mattress that is too soft for a particular body type and sleeping position will provide poor support under other the heavier and more “protruding” parts of the body. One of the two main functions of a mattress is to keep you in good alignment in all your sleeping positions (the other is to provide good pressure relief in all your sleeping positions) and this needs a combination of good primary support under the heavier parts of the body and good secondary support under the more recessed parts of the sleeping profile.

Every layer and component in a mattress will have some effect on every other layer both above and below it and when you are dealing with multiple layers this can become very complex and is as much as art as a science. There is more about primary or “deep” support and secondary or “surface” support and their relationship to firmness and pressure relief and the “roles” of different layers in a mattress in post #2 here and in post #4 here that may also be helpful in clarifying the difference between “support” and “pressure relief” and “feel”.

I would also be very careful about using ILD specs by themselves as a basis for comparison because ILD is only one of several factors that is part of how soft or firm a layer or a mattress will feel (see post #4 here). ILD ratings are also not directly comparable between different types of latex or between different types of foam (see post #6 here).

Unless you have a great deal of knowledge and experience with different types of mattress materials and specs and different layering combinations and how they combine together and can translate them into your own “real life” experience that can be unique to you … I would tend to avoid using ILD numbers or other complex specs to try and predict how a mattress will feel or perform for you and focus more on your own actual testing and/or personal experience. When you try and choose a mattress based on complex combinations of specs that you may not fully understand then the most common outcome is information overload and “paralysis by analysis”.

To help you bypass all the more “technical stuff” though … there is also more information in post #2 here about the different ways to choose a mattress (either locally or online) that is the best “match” for you in terms of PPP that can help you assess and minimize the risks of making a choice that doesn’t turn out as well as you hoped for that are involved in each of them.

When you can’t test a mattress in person then the most reliable source of guidance is always a more detailed phone conversation with a knowledgeable and experienced retailer or manufacturer that has your best interests at heart and who can help “talk you through” the specifics of their mattresses and the options they have available that may be the best “match” for you based on the information you provide them, any local testing you have done or mattresses you have slept on and liked that they are familiar with, and the “averages” of other customers that are similar to you. They will know more about “matching” their specific mattress designs to different body types, sleeping positions, and preferences (or to other mattresses that they are familiar with) than anyone else without you needing to first go through the learning curve about mattress theory and design and the many complex specs that may be involved.