Mattress Foam Density Explained

What foam density can tell you, what it cannot, and why density is different from firmness.

Density and firmness are different measurements

Density describes mass per unit volume. Firmness describes resistance to compression under a specified test. A denser foam is not automatically firmer.

Why shoppers see density figures

When manufacturers disclose them, density numbers can provide additional context about a foam layer. They should be considered alongside formulation, layer thickness, position in the mattress and intended function.

Avoid false precision

One density number does not determine the quality or durability of an entire mattress. Construction is a system.