Memory Foam vs. Innerspring: 5 Key Differences
First, the easy one: As the names suggest, the chief difference between a memory foam mattress and an innerspring is the material. One is made of layers of polyurethane foam, while the other is built atop a core of coiled metal springs.
But that basic difference gives rise to a host of others, such as how each type of mattress feels, the way it supports your body, and what kinds of sleepers tend to prefer one over the other.
If you're trying to make a decision for your next bed but it’s still a battle of spring vs foam mattress, here's a rundown of the key distinctions.
Memory foam vs. innerspring construction
Memory foam, also called viscoelastic foam, is high-density polyurethane foam that responds to heat and pressure. Its chief characteristic is the ability to "mold" to the body's contours, which makes it the material of choice for many people with back and joint pain.
Most memory foam mattresses are not 100% viscoelastic foam; if they were, they would be so soft that you'd sink down too far into the surface. Typically, a quality memory foam mattress has a support core of polyurethane foam and a top layer—or multiple layers—of high-density memory foam (4 to 5 pounds per cubic foot).
(For a closer look at memory foam, see How to Pick the Perfect Memory Foam Mattress)
Innerspring mattresses at their core contain a series of steel coils or springs that give shape and support to the bed. The coils are topped with layers of padding, foam, and sometimes even additional springs (as in Saatva's coil-on-coil design). Coils can be open or individually "pocketed." Pocket coils have two advantages: Because they can move independently, they do a better job than old-style "open" coils of conforming to your curves, and they also reduce motion transfer, so you're less likely to feel the movements of someone else in the bed.
(For a closer look at innersprings, see How to Pick the Perfect Innerspring Mattress)
Memory foam vs. innerspring: how to choose
While there are some essential differences between mattress types, there is also enough variety within each category that no one type of mattress is best for any one type of sleeper. "I've had people tell me a certain innerspring is terrible for their back, and others say it was the best thing for their back," says Terry Cralle, RN, a certified clinical sleep educator and co-author of Sleeping Your Way to the Top.
To make the right choice, you'll have to consider your sleep style and comfort preferences. For example:
- Whether you'd rather sink or spring. Some people love memory foam's body-hugging feel; others, not so much. The good news here is that, while innersprings will always be "bouncier" than foam, many newer innerspring designs feature foam comfort layers that offer some of the best of both worlds: innerspring's responsiveness with foam's cushioning and pressure-relieving qualities. So while you may associate innersprings with the stiff, squeaky beds you jumped on as a child, Cralle says, today's models won't necessarily feel that way.
- If you "sleep hot." Memory foam mattresses are known for "sleeping hot," as the dense foam tends to trap body heat. Innerspring mattresses, on the other hand, have more open space within the bed where air can circulate, which helps keep things cool. Here again, technology has changed the picture, with the advent of cooling gels and other materials, such as bio-based and "convoluted" (i.e., egg-crate) foams that dissipate heat.
- Whether you share your bed with a partner: One major brag for memory foam mattresses is how well they handle motion transfer, meaning that someone sleeping on one side of the bed feels little to no movement when the person on the other side tosses and turns or gets up in the night. Innerspring mattresses in the past performed a lot worse on this score, but pocketed coils, better coil design, and foam comfort layers can help isolate motion and minimize disturbances.
- If you have back pain or other orthopedic conditions. “Some people with back and joint problems enjoy the better support of their affected areas with a memory foam mattress," says Mark I. Leavey, MD, a primary care specialist in Lutherville, Md. Be aware that if you tend to move around a lot during the night, you may find the "memory" aspect of memory foam annoying, since it takes a few minutes for the foam to adapt to a new position.
Learn More About Saatva's Innerspring and Memory Foam Mattresses
What memory foam and innerspring mattresses cost
Both memory foam mattresses and innersprings run the gamut for cost and average lifespan for mattresses, depending on quality. A higher price tag doesn't necessarily mean a higher quality product, Cralle says. (Where you buy it can make a big difference on that front.)
Rather than focus on cost, she says, do your homework to find out exactly what materials are inside the mattress, read quality reviews from other customers about how the mattress wears (not comfort reviews, which are subjective), and make sure you've spent an adequate amount of time living with the bed to know that you find it comfortable. (That's why generous return policies of 100 days or more are so important.)
Finally, it's important not to typecast yourself into any single category of mattress, Cralle cautions, even if you've always slept on a certain type in the past. “There are so many new materials and technologies out there," Cralle says. “You might want to just try another. You may be surprised."