Latex Mattress Firmness Ratings – What are ILD’s and What do they mean?

When shopping for a new latex mattress, you may come across the term “ILD firmness rating” in relation to latex mattresses. But what exactly does this mean and how does it affect your sleep experience? In this article, we’ll dive into the world of ILD ratings and explain why they are important when choosing a latex mattress.

What is an ILD Firmness Rating?

ILD stands for “Indentation Load Deflection” and is a measurement used to determine the firmness of a mattress. It is also known as IFD (Indentation Force Deflection) or IFD rating. ILD is measured by placing a circular disc on top of the mattress and measuring how much weight is needed to compress the disc by 25%. The higher the ILD number, the firmer the latex mattress is or the piece, slab or core of latex.

How is ILD Measured?

ILD is measured in pounds, with most latex mattresses having an ILD rating between 20-50. The measurement is taken at different points on the mattress, typically in the center and at the edges, to get an overall average. This is because the firmness of a mattress can vary depending on where you are lying on it. The sides will be softer than the center of the latex.

What Does the ILD Rating Mean for Your Sleep Experience?

The ILD rating impacts you because you will want your mattress made with the right ILDs for the type of firmness you want in your latex mattress. A higher ILD rating means a firmer mattress, while a lower ILD rating means a softer mattress. The ideal ILD rating for you will depend on your personal preferences and sleeping habits. ILD is only for rating latex. Memory foam mattresses use a different scale.

Back Sleepers

Back sleepers generally prefer a firmer mattress, with an ILD ranging from 35 – 44. 44 is the firmest ILD.

More on Sleeping on Latex for Back Sleepers.

Looking for a good Latex Topper for Back Sleeping?

Side Sleepers

Side sleepers typically prefer a softer mattress, with an ILD rating between 14-24. This allows for more sinkage to cushion the shoulders and hips, which can often bear the weight of the body in this sleeping position. Please note this is the recommended ILD for the top layer or two of the latex mattress which make up the comfort layers. You will want a higher ILD on the bottom support layers.

Also, soft mattress sleepers will tend to do better with Talalay Latex for the top comfort layers while Dunlop with a higher ILD is great for the bottom layer or layers.

Information on Sleeping on Latex for Side Sleepers.

Latex toppers pointers for Side Sleepers.

Stomach Sleepers

Stomach sleepers prefer a firmer sleeping surface so an ILD rating between 26-32 is recommended for top comfort layer for stomach sleepers. However, stomach sleepers like a little cushion under the firmer sleeping surface so they will typically go for a softer second layer or middle layer(s) with an ILD range of 19-24.

More on Sleeping on Latex for Stomach Sleepers.

The Best Latex Topper for Stomach Sleepers.

Combination (Toss and Turners) Sleepers

If you tend to switch between sleeping positions throughout the night, a medium-firm mattress with an ILD rating between 25-32 is a good choice for your top comfort layers. This will provide adequate support for all sleeping positions without being too firm or too soft. Especially with the higher ILD Dunlop support layers on the bottom.

How Does ILD Affect the Durability of a Latex Mattress?

ILD can also play a role in the durability of a latex mattress. A higher ILD rating means a denser and more durable mattress. This is because the higher the ILD, the more latex is used in the mattress, making it more resistant to wear and tear. In other words, the higher the ILD of the latex the longer it will last.

Conclusion

In summary, ILD stands for “Indentation Load Deflection” and is a measurement used to determine the firmness of a mattress. A higher ILD rating means a firmer latex mattress, while a lower ILD rating means a softer latex mattress. Primarily ILD doesn’t refer to the actual mattress itself with the cover on it but more so just the latex. Rating the 3-inch layers and 6-inch cores, etc.

The ideal ILD rating for you will depend on your personal preferences and sleeping habits. By understanding ILD ratings and considering these other factors, you can choose the perfect latex mattress for a comfortable and restful night’s sleep.

Here’s a short video on Why to Choose a Latex Mattress.