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Memory Foam Density and Quality Explained

June 26, 2018   By Ecosa Dream Writers

Mattress-shopping will have you come across technical or numerical terms that seem quite a challenge to understand. Foam density is one of them – I’d say one of the most important ones. The topic itself is complex, so I tried debunking the most common misconceptions regarding density by explaining them with illustrations and examples.

What’s Foam Density?

We know from primary school science that density refers to the compactness of a material or the mass per unit volume of an object. In mattress terms, it means the mass of a cubic metre section of a mattress measured in kilograms per cubic metre (kg/m3). Say, if a foam is 50kg/m3, that means each cubic metre of the foam weighs 50 kg.

Misconception #1: Firmness Is Not Equal to Density

A common misconception of many is that a higher density denotes a higher firmness level. This isn’t necessarily true. Imagine two cubes: one filled with feather and the other filled with rocks. These both have a density of 30kg/m3. Having similiar densities doesn’t mean the feather cube will be as firm as the rock cube is.

Firmness is not equal to density

For reference, densities are categorised into three: low, medium, and high. This is an industry standard and you can ask companies for this if it’s not yet stated in their specifications.

Density Classification & Density in Units

  • Low Density (30kg/m3 and lower)
  • Medium Density (30kg/m3 – 50kg/m3)
  • High Density (50kg/m3 and higher)

Misconception #2: Density Is Not Equal to Quality

Be careful not assume from the table above that a low-density foam will be a low-quality foam. That’s yet another misconception – a higher density foam DOES NOT mean a higher quality foam either. 

If we go back to the example of feather and rock cubes that have the same density, sitting on the feather cube might cause you to sink to the bottom almost immediately – leading you to think that it is lesser in quality than the rock cube that can hold you up. But the thing about quality is it depends on the factor you’re measuring – is it durability? raw materials? comfort? sleep quality?

The Bread Example

To make the differentiation between density and quality better, I’ll lay out a new example – baking bread. In baking, you’ll need a secret recipe, good-quality dough, and other ingredients along with a top-notch cook to make great bread.

The same is true for foam – its quality will depend on the specific aspect of the foam you’re looking at. Quality cannot be defined by density alone, but also on other factors such as durability, the raw materials used, method, foam mix, and even equipment/technology.

Indicators of Quality

Raw Materials

Look into factors such as the kind of foam used (memory foam, latex, synthetic/natural foam), and the adhesive/glue used (if it’s chemical or water-based). If the mattress is multi-layered, educate yourself with each foam layer’s specs and whether it is consistent in quality with the other layers or not.

Companies are not always likely to share this information out in the open, so make sure to ask!

The Mattress Construction

As in the baking example, a good mattress company needs a ‘secret recipe’ that outlines the entire make-up of their mattress. This includes details on the formula and cutting-edge technology (like Open-Cell Technology) behind the mattress that cannot be done without highly-skilled engineers and craftsmen.

Our insider informants (aka our manufacturers and engineers) tell us that each layer of foam is even carefully-selected to match the mattress’ design. Suffice it to say, mattress construction is where science and art meet!


You can expect more durability in a mattress that is well put-together. When buying a one, check out the warranty period offered. It’s likely that a mattress will be able to last (or even outlast) its warranty period when properly taken care of.

RELATED ARTICLE: The Pros and Cons of Memory Foam

Final Notes

Below is a recap of all things we learned today.


I hope it helps you come to mattress decisions based on fact. As a last reminder, don’t forget to check honest customer reviews. No one can vouch for the quality of a mattress better than people who actually use it.

When in doubt, just remember our illustrations feather & rock cubes, and bread-baking!

(If you ever need an example of a high-quality memory foam mattress, just come through our way. *wink*)

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