Memory Foam Mattress Buying Guide

What is memory foam?

Memory foam is a viscoelastic material that adjusts and conforms to the contours of the shape pressed against it. Visco (thick, resistance to change) elastic (returning to shape after distortion).

The difference between memory foam and regular foam is the character of response. Regular foam will return to shape immediately and can be likened to the inserts in a couch cushion. In contrast, memory foam has a much higher capacity to adjust to pressure and contours of the body.

You can benefit from memory foam if you are uncomfortable in a spring mattress, toss and turn at night, have back, shoulder, or neck pain, or if you need additional pressure relief and comfort to help you sleep.

The feel of memory foam is determined by three things that include Density, Firmness, and layer thickness.

What's the real history of memory foam?

Memory foam was originally developed for NASA by a company called EAR Specialty Composites. The resulting CONFOR Foam is a slow recovery foam that's used to protect components from damage by dampening impacts. NASA saw the advantages of supporting and protecting their astronauts during launch and re-entry.

Following that realization, the use of memory foam in the seating and instrument protection spread to nearly all aircraft, especially in military aircraft such as jets and helicopters where pilots are subjected to high g-forces.

Later, once production resulted in pricing that made it affordable, engineers made some modifications to the foam composition and translated it for use in the bedding industry.

Density: Facts and fiction

Density is a measure of weight (pounds per cubic foot). Many densities are available that usually range from 3lb to 7lb. The ideal density and industry standard is between 4lb to 5.3lb which is what Tempurpedic and Amerisleep use.

The difference between lower density foam and higher density foam is the memory characteristics. Lower densities will have less of a "memory" to the foam when compared to higher density foam.

Typically, denser foams greater than 5.3lb will cause the user to feel more "stuck" in the mattress when compared to the alternative - mattress that uses foam between 4lb and 5.3lb.

FACTS

  • Density affects memory characteristics
  • Affects cost of the mattress
  • Ideal density and industry standard is between 4-5.3lb
  • Denser foams will cause the user to feel more "stuck" in the mattress

FICTION

  • Higher density is always better
  • All density is created the same
  • Density is a reliable indicator of quality
  • Density is the only factor that affects the comfort.

How to choose the best firmness

Since the firmness of memory foam fluctuates depending on temperature, the best way to measure firmness is based on the thickness of the support and thickness of a memory foam layer on top.

You're probably asking yourself, "So what firmness is right for me?"

The best way to determine the right firmness is to start by deciding how your current mattress either satisfies or causes discomfort. From there, check your sleeping position. Consider your body's shape and match it with the correct firmness to give you proper spinal alignment.

Of course, you may find that your taste is different. That's okay! From plush to firm, we've selected the ideal range of choices to satisfy any comfort need.

THE BEST FIRMNESS

Consider your body's shape and match it with the proper firmness to give you proper and natural spinal alignment.

How thick should a memory foam mattress be?

In addition to the density, the feel of a mattress, despite many advertisements and marketing schemes, is based on the ratio and firmness of memory foam and supporting layers.

Based on consumer reviews and ratings, we've found that the ideal mattress will have between 2" and 7" of memory foam on top of the support layer. Typically, with a thicker layer of memory foam, you'll experience a softer feel. With a thinner layer, you'll be closer to the support layer resulting in a firmer feel.

Memory foam mattress thickness guide

IFD: What this should mean to you

Indentation Force Deflection (IFD) is the amount of force, in pounds, that is needed to indent a round indenter foot into a foam sample a certain percent of the total thickness. Essentially, the machine that measures the IFD is measuring the perceived firmness of the sample. As the "foot" presses down into the foam, it measures the resistance and how much force is required to press the sample downward. Higher ratings (such as 30+) are firmer while a lower rating (25 or less) is softer.

Simply put, the IFD rating of the foam will determine the feel of the mattress. A higher number translates to a firmer feel while a lower number produces softer feel. However, it is not a complete measurement of a "soft" or "firm" feel. A higher IFD rating of a lower density foam can feel soft when compressed.

So why do you care about the IFD?

You care because it's a measure of firmness, usually associated with layers in the mattress. A higher number is firmer while a lower number is softer.

IFD's Effect on Firmness

A higher number is firmer while a lower number is softer.

Is it time to replace your foundation / box spring?

Good news! You may be able to use your existing foundation so long as the following is true:

  • No more than 8-10 years old
  • Has a steady, flat surface
  • No springs
  • Solid construction (no cracks/splinters/breaks)

You wouldn't buy a new car with old shocks. A foundation helps prevent sagging. So it's important to maintain a quality supportive surface for your mattress. Don't risk the durability and warranty of the mattress.

If in doubt, throw it out.

Compare our mattresses

Model
Reviews
Firmness
Learn more
Sleep Style
Learn more
Profile Height
Learn more
Layer Construction
Learn more
Cover Fabric
Learn more
Fire Guard
Learn more
Bio-Pur™ HD Comfort Layer
Learn more
Bio-Pur™ Comfort Layer
Learn more
Bio-Core™ Base Layer
Learn more
Price1 (Mattress Only)
Review Snapshot
Firm
Stomach, Back
8-inch
2 layers
Breathable fabric cover
Green Guard fire sock
N/A
2 inches
4.5-lb density
12 ILD
6 inches
2.0-lb density
35 ILD
Twin: $449
Twin XL: $499
Full: $599
Queen: $649
King: $749
California King: $749
Split King: $998
Show moreless sizes Shop Columbus
Review Snapshot
Firm
Stomach, Back
10-inch
2 layers
Breathable fabric cover
Green Guard fire sock
N/A
3 inches
4.5-lb density
12 ILD
7 inches
2.0-lb density
35 ILD
Twin: $499
Twin XL: $549
Full: $699
Queen: $799
King: $899
California King: $899
Split King: $1098
Show moreless sizes Shop Americana
Review Snapshot
Soft
Side, Combo
12-inch
2 layers
Breathable fabric cover
Green Guard fire sock
N/A
3 inches
4.5-lb density
12 ILD
9 inches
2.0-lb density
28 ILD
Twin: $680
Twin XL: $730
Full: $930
Queen: $1030
King: $1230
California King: $1230
Split King: $1429
Show moreless sizes Deal of the day! Shop Liberty
Review Snapshot
Medium Firm
Back, Combo
12-inch
2 layers
Breathable fabric cover
Green Guard fire sock
N/A
3 inches
4.5-lb density
12 ILD
9 inches
2.0-lb density
35 ILD
Twin: $730
Twin XL: $780
Full: $930
Queen: $1130
King: $1330
California King: $1330
Split King: $1529
Show moreless sizes Shop Revere
Review Snapshot
Soft
Side, Combo
14-inch
3 layers
Natural bamboo, cotton blended
Green Guard fire sock
2.5 inches
5.3-lb density
10 ILD
3.5 inches
4.5-lb density
12 ILD
8 inches
2.0-lb density
35 ILD
Twin: $1180
Twin XL: $1230
Full: $1430
Queen: $1730
King: $2030
California King: $2030
Split King: $2429
Show moreless sizes Shop Colonial

1Prices reflect current promotion or sale.

Call Amerisleep

Get answers about Amerisleep mattresses before you buy.

1-800-500-4233