Memory Foam Mattress Density – What you need to know

Last Updated: August 2017

Memory foam mattresses are all the rage currently. They promise a lot and deliver on their word, however they are not exactly easy to buy, and seeing as they offer more and more features and added extras, it’s often hard to tell the difference between what we actually need and what we actually want.

First thing’s first, memory foam mattresses come in 3 density ranges, they are either low, medium or high density memory foam. What this density refers to is not the size of the actual mattress but rather how dense the foam is.

It might vary a bit if the foam is gel foam or actual foam, however the same general rules apply, and there are still some things that you need to know before you rush off to buy yourself a memory foam mattress.

Mattress lifespan

Because denser foam means more structural strength, it comes as no surprise that the denser the foam is the bigger the lifespan of the mattress.

On average, based on normal usage conditions and stress, low density mattresses will last around 5 years, a medium one will last you around 7-8 years and a high density one will last you 10 years.

Due keep in mind that this is an average based on average use, taking into consideration the sagging, average humidity, and wear and tear.

Heat retention

One of the most important things that you have to keep in mind when buying a mattress is the amount of heat that it is capable to retain while you sleep.

It’s not that you might end up cold over the night, but rather that you might end up too hot for comfort.

You do run the risk of waking up in a puddle of sweat, not to mention the fact that you will toss and turn constantly in your sleep in order to cool off, making for a rather uncomfortable experience.

Again, the denser the foam used, the more heat will be retained, so high density ones are the ones to watch out for.

A good tip would be to make sure that the mattress is properly ventilated before purchasing it and you will be ok.

Pain relief

A lot of people are suffering from lower back problems, and rightfully so when you count the amount of hours we spend sitting on an office chair.

One of the trademark features of memory foam mattresses is the fact that they can relieve shoulder, hip and back pain fairly easily, and all 3 densities are quite close to one another in that aspect.


Leaving everything else side, what it all boils down to at the end of the day is a good night’s sleep, which cannot be achieved without a certain level of comfort.

For that, you need the mattress to be a bit soft, ventilated, and able to vent out excess heat.

Out of all 3 of them, the medium density mattresses are the ones that are coming out shining. They are not too soft nor too firm, having just the right amount of foam to make it a comfortable experience, and at the same time trapping the right amount of body heat for a comfortable night’s sleep.

The Innovation Of Memory Foam

Most of the memory foam industry can give thanks to the innovations of the TempurPedic company. In the 1980s, they were the industry leader of medically useful mattresses and developed a “visco-elastic” foam, that would later become dubbed “memory foam“. This foam was an open-celled combination of polyurethane and other agents that would create a mattress firm enough and supportive enough to sleep on, with no pressure points. The material became instantly useful in wheelchair cushions, hospital beds, and disability cushioning.

Over the years, competitors have risen and developed their own proprietary combinations of materials to create their specific blend of memory foam. Many, including TempurPedic, started adding latex to their mattresses to improve airflow and support at different layers.

Why Two Layers Of Different Density Memory Foam?

Through our research at Memory Foam Doctor, we’ve discovered that the less dense layer of memory foam on top made our mattress soft initially, while adding enough support for the average individual. We determined that in order to offer more support and maintain that initial softness on lying down, we need to use a more firm layer underneath our softest top layer. When you lay down on a memory foam mattress, you’ll initially feel the stiffness of the memory foam, then as the cells start to “squash” they develop a supportive cradle that contours to your body. We wanted the top layer to be soft as your favorite inner spring, while the second layer would offer the supportiveness you were looking for from a firmer mattress. In essence, we’ve structured our mattress as such to offer the best of both worlds.

The thinner density of the top layer (4 lbs), allows for more dissipation of body heat and improved airflow, while also creating that softer feeling you would get with a down top on an inner-spring mattress. The thicker density layer creates more of the support you’ve come to expect and appreciate from memory foam mattresses, without the rigidity and pressure points created by an inner-spring mattress of comparable firmness.


Different memory foam densities in memory foam mattresses are a good thing because it not only provides the buyer with multiple choices, but rather because it also allows the buyer to actually purchase a mattress according to his/her requirements.

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