Memory Foam Toppers

What is ILD?

ILD is mentioned in relationship to memory foam, but what does it mean? Is it important? The simple answer is: Yes, it's important. Let's learn how.

ILD stands for Initial Load Deflection, which is a scientific way of saying Initial Softness or Surface Feel. ILD is a measurement of how much pressure it takes to compress memory foam by 25%.

ILD measures the strength of that top section of the foam (the blue part above), which is the part you feel when you push on a mattress or topper with your fingers. It's the initial feel of the foam.

MemoryFoam.com memory foam is rated at 15 ILD, which is widely considered the optimal rating for use in sleep products.

If the toppers are all the same ILD, then why would I choose one over the other?

Great question! ILD is not the most important factor in a buying decision. It's only the "showroom" feel, but even cheap foam can be made to feel good just with ILD. But that's no indication of how well it will perform over time for your body.

No, what you really need (what your body needs) is support. You need your memory foam to be able to lift your body weight and cradle you in comfort along the contour of your body shape, without bottoming out and creating pressure points.

How do I get better support?

Now we're getting somewhere. If ILD is the rating of the first 25% of the foam, the initial feel, then what we're after is the rest of the foam. Fortunately, there is another rating called the Support Factor that measures exactly that.

Support Factor

Support factor measures the pressure it takes to compress memory foam by 65%. This is an indication that far surpasses the initial 25% ILD rating. This Support Factor is the better measurement when you are deciding how the foam will work for you.

What's the key to getting better support?

Simple. Density is the key to Support. Remember, density is how much stuff is inside your memory foam...the thickness or weight of it. It turns out that having more stuff inside the foam directly affects the support of the foam. Higher density equals higher support.

Does "more support" mean "more firm?"

NO! This is the biggest misconception in the memory foam market today. ILD and Density are 2 completely separate values that can be controlled in the manufacturing process. You can have hard foam that's low weight, and you can have soft foam that's high-density. There is no relationship between Feel and Support.

This is how we can maintain an optimal 15 ILD across the board, and still offer a more supportive memory foam as you go up in density.

So, how much support do I need?

Now here's the million-dollar question! Now that you know that feel is independent of support, and that support is actually the more important factor, we need to find out how to find the right one for you.

We all come in different shapes and sizes, have different sleeping styles, different needs, and personal tastes that go into the buying decision. We're going to take all these factors into play and use them to make sense of the different options.

1. Body Type

The best place to start is with body type. When we talk about "support," we're talking about the memory foam's ability to balance weight that is dispersed over a surface area. A heavier body weight will require more support than lighter weight to achieve the optimal spinal alignment that we all need. So Body Weight is one factor to consider.

2. Sleeping Style

When you sleep on your back, you take your body weight and disperse it over the surface area where your body touches the mattress. However, if you sleep on your side, you are actually taking that same body weight and intensifying it in a smaller surface area. In this case, you would need a higher support rating. Remember, the surface feel doesn't change (all the beds are rated at an optimal 15 ILD "feel), but the supportiveness of the foam increases with a higher support rating.

3. Personal Needs

If you have special medical needs, or have a condition that requires additional support, you would look to higher densities in your memory foam mattress. If you have had back surgery, for example, you might consider a higher support rating to ensure proper spinal alignment.

4. Preference

This is the ultimate decision maker: your preference. If you like to sleep more on top of the bed, or if you gravitate to firmer mattresses, then you will be more comfortable with a higher density memory foam mattress. If you tend to buy more plush pillowtops and like that sink-in feeling, then you might step down to a medium or light support mattress.

Remember, the feel of the foam doesn't change, but the support or "buoyency" of the foam does. Higher densities resist body weight more and do a better job of lifting you up. Lower densities allow you to sink in farther.

If you have any questions, please call one of our trained sleep professionals at 1-888-MEM-FOAM (636-3626)