Mattress Firmness Guide

Understanding the firmness scale

Mattress firmness is usually described on a scale from soft to extra firm, with plush, medium-soft, medium-firm, and firm as the common stops in between. There's no universal numeric standard across brands, so the same "medium" label can feel different from one manufacturer to the next — which is exactly why lying down on the actual mattress matters more than the label on the tag. You can browse the full range in person across our mattress collection, from plush pillow-tops to firm support cores.

Firmness by sleep position

Sleep position determines where your body needs the most cushioning and where it needs the most support, so it's the natural starting point for narrowing down firmness.

Side sleepers: plush to soft

Side sleeping concentrates weight on the shoulder and hip. A plush or medium-soft mattress lets those points sink in slightly so the spine stays in a straight line from neck to hip, rather than bowing because a firm surface is holding the shoulder up higher than the waist.

Back sleepers: medium-firm

Back sleepers need a surface that supports the natural curve of the lower back without letting the hips sink too far. Medium-firm is the most common recommendation because it balances light cushioning at the shoulders with enough support to keep the spine neutral.

Stomach sleepers: firm

Stomach sleeping puts the most strain on the lower back if the mattress is too soft, since the hips and midsection are the heaviest part of the body and will sink first. A firm mattress keeps the midsection from dropping out of line with the shoulders and legs.

Body weight and partner differences change the answer

Sleep position is the starting point, but it isn't the whole story. Two people with the same sleep position can need different firmness levels because of body weight and personal comfort.

• Lighter sleepers often feel a mattress as firmer than a heavier sleeper does, since less weight compresses the comfort layers less deeply
• Heavier sleepers may need a firmer core or thicker support layer to avoid sinking too far, even if they favor a plush feel on top
• Couples with different preferences can look at dual-firmness or split mattresses, or a hybrid with zoned support, rather than compromising on a single middle-ground feel

If you're furnishing more than the mattress itself, our bedroom collection has frames and storage beds sized to match, and a hands-on mattress fitting appointment is the easiest way to sort out a two-person decision with a sleep specialist in the room.

Firmness vs. support: they aren't the same thing

It's easy to assume a firmer mattress is automatically more supportive, but firmness and support describe two different things. Firmness is how the surface feels when you first lie down — soft or hard to the touch. Support is whether the mattress keeps your spine aligned once you're lying in your normal position for a full night. A mattress can feel firm yet still lack the structural support to keep hips from sagging over time, and a plush mattress can be well-supported if its underlying coil or foam system is built correctly. When testing a mattress, pay attention to spinal alignment, not just the initial softness of the surface.

Materials affect firmness and feel

Innerspring

Traditional coil support with a comfort layer on top. Innerspring mattresses tend to feel more responsive and sleep cooler, and firmness is largely set by coil gauge and the comfort layer thickness.

Hybrid

Combines a coil support core with thicker foam or latex comfort layers, offering a wide range of firmness options with the airflow benefits of coils underneath.

Foam

All-foam mattresses contour closely to the body and isolate motion well, which side sleepers and couples often appreciate, though firmness needs to be chosen carefully since foam has less inherent bounce than coils.

Two-sided

Two-sided, flippable mattresses are built to be used on both faces, and some models offer a different firmness on each side — a practical option if you're unsure which feel you'll prefer long-term.

How to test firmness in a showroom

• Lie down in your actual sleep position — not on your back if you sleep on your side — and stay there for several minutes, not a few seconds
• Bring or wear clothing similar to what you'd sleep in, and try to relax fully rather than staying tense while testing
• Check whether your spine feels level from shoulder to hip, and whether pressure points like the shoulder or hip feel relieved or still loaded
• If you sleep with a partner, test the mattress together, since one person's movement and warmth affect the other's experience
• Ask about the return or comfort exchange window before you buy, since a few minutes in a showroom is still shorter than a night at home

Adjusting firmness after the fact

If a mattress you already own feels slightly off, small adjustments can help before you replace it outright. A mattress topper can soften a surface that feels too firm, while a firmer foundation can add support under one that feels too soft. An adjustable base can also change how a mattress feels by elevating the head or feet, which shifts pressure distribution even though it doesn't change the mattress's underlying firmness. These are adjustments rather than full fixes — if the core feel is simply wrong for your sleep position, it's usually time to shop for the right mattress from the start.