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Memory Foam Mattress Density: Low Vs Medium Vs High → Comparison Based on Data From 5,650+ Owners
Page last updated October 10, 2011
What You Need To Know
In most areas of comparison, low- and medium-density memory foam mattresses tend to perform as well as, and often better, than high-density memory foam mattresses.
As a result, low- and medium-density mattresses are increasingly popular, while high-density beds appear to be losing ground.
To learn the density of many popular memory foam mattresses, see the memory foam mattress ratings – summary.
WHAT IS memory foam density and WHY is it important?
Density indicates how much the foam weighs. For example, a cubic foot of 4 lbs/ft density foam weighs four pounds.
Foam density, owner data shows, is responsible for many mattress characteristics and for many of the differences between memory foam mattress brands / manufacturers. In many cases, you can learn much about a memory foam mattress simply by knowing its density.
Memory Foam Density Comparison: Summary
The findings below are based on a sample size of at least 5,650 actual memory foam mattress owners. Owner experience data was collected from diverse, credible sources. The findings are true for memory foam mattresses as a group; individual brands and owner experiences may go against these findings somewhat. Refer to the comparisons below this table for more detailed analysis.
| Low Density (2.5 - 3 lbs/ft) |
Medium Density (4 lbs/ft) |
High Density (5 lbs/ft +) |
|
| Owner satisfaction | Good | Good | good |
| Price | good-Fair | fair-Good | Poor-Fair |
| Durability / longevity | fair-Good | Good-fair | good |
| Less (back) pain | good-fair | good | good-Excellent |
| No initial odor | good-fair | fair | Poor-Fair |
| Motion isolation | good | good | good |
| Not a heat trap | good | good-fair | fair |
| Not overly firm | fair-good | good | good-fair |
| Not temperature sensitive | good-fair | fair | Poor-fair |
| Easy to move on | good | good-fair | fair |
| Lightweight | fair | fair-poor | poor |
| Good for sex | good-fair | fair-good | fair |
| Brand selection | good | good | Poor |
| Warranties | fair-good | good | good |
Owner Satisfaction
Memory foam mattresses, regardless of their density (low, medium or high), often have about the same owner satisfaction rate – around 80%. Although the mattresses have similar owner satisfaction, they often have fairly different strengths, weaknesses and characteristics depending on their density. (Refer to the rest of this page and the next page for a description and comparison of these differences.)
Price
The price of a memory foam mattress is often linked to its density. The more dense the memory foam, the more expensive the mattress usually is.
Higher-priced brands will tend to use higher-density memory foam (5 lbs/ft or greater in significant quantity); medium-priced brands will tend to use mostly medium density (4.0 lbs./ft); and lower-priced brands will tend to use mostly lower density (2.5 - 3.0 lbs./ft).
There are some mattress brands that claim to use higher-density foam, yet their price is similar to lower-density foam mattresses. It is wise to be skeptical of these claims and verify them the best you can.
Durability / Longevity
On average, the higher the memory foam density is, the better the durability / longevity of the mattress.
Mattresses with high-density foam can generally be expected on average to remain supportive and comfortable for around ten years.
In 10-15% of owner experiences, however, higher-density mattresses lose comfort and support sooner than ten years (sometimes much sooner) due to premature sagging and or premature softening.
Memory foam mattresses with low and medium density on average have a shorter lifespan, often in the 4-8 year range. This is only an average, however; the longevity of a particular low- or medium-density mattress can vary from the average considerably.
A fairly accurate way to determine the expected longevity of a particular mattress is to refer to the non-prorated length of its warranty; this is often the length of a bed's useful life. For example, a mattress with a non-prorated warranty of ten years will likely last on average about that long.
Pain Relief, Including Back Pain Relief
All memory foam mattresses, regardless of density, usually rate well in regard to pain relief, including relief of back, shoulder and hip pain.
However, the higher the density of foam, the better the pain relief potential is in most cases. This is because higher-density foam tends to strongly conform to the contours of a person's body which can result in excellent support, including optimal spinal alignment and minimization of pressure points.
Initial Odor / Off Gassing
Owner data suggests that, generally speaking, the more dense a memory foam mattress is the longer and or more strongly it will give off an initial chemical-like odor or gas. More info: memory foam mattress off gassing.
Memory Foam Density Comparison Continued >