What Are the Differences Between Innerspring and Memory Foam Mattresses?

Innerspring mattresses have been around for over a century, and many people still favor them today. However, they face increasing competition from memory foam. Its popularity has exploded in popularity in recent years, especially in the online marketplace. In terms of feel, innerspring and memory foam mattresses are probably as different as two mattress types can be. Which one is right for you depends entirely on your preferences and sleep style. Read on to learn more about each type and how they differ.

Memory foam—or viscoelastic polyurethane foam—is a type of polyfoam that was developed by NASA in the 1960s. “Viscoelastic” means that it changes shape when pressure or heat is applied. It’s soft like other foams, but has been treated with petrochemicals to make it denser and more viscous. It’s also “open-cell,” meaning it’s filled with small holes that help circulate air.

Because of its construction, memory foam is very adaptable. When met with body heat, it conforms closely to a sleeper’s body, and it returns to its normal form when it cools. Its excellent contouring abilities make memory foam great at pressure point relief. This is especially important for side sleepers, who often experience pressure at the shoulders or hips. It can also be helpful for those who have neck or back pain. Memory foam tends to learn a sleeper’s body over time and re-conform to it each time he or she gets into bed.

Memory foam mattresses aren’t constructed entirely of memory foam. It needs a more supportive material to complement it. High-density polyfoam usually comprises the support core in these mattresses. The transitional layer is often made of memory foam or polyfoam, and memory foam makes for a plush, conforming comfort layer.

Innerspring mattresses have been around since the early 1870s. While there’s some variation among specific models, all innerspring mattresses follow a similar basic construction. A support core of metal coils sits beneath a comfort layer that is usually made from a softer, more responsive material, like polyfoam, memory foam, or latex. This comfort layer is 2” or fewer, which distinguishes an innerspring mattress from a hybrid, which has a thicker comfort layer. High-density polyfoam is usually used as a base layer and to reinforce coils at the borders of the mattress.

There are four main types of coils:

• Bonnell Coils: The oldest and often cheapest design, bonnell coils are hourglass-shaped and connected with spiral-shaped wires, called helicals.
• Offset Coils: These are similar to bonnells in that they’re hourglass-shaped and connected with helicals, but the bottom of each coil is flattened to create a hinging effect when the coil is flattened. This makes for a very durable—and more expensive—design.
• Continuous Wire Coils: These include long rows of single wires in circular shapes that are connected by helicals. Mattresses with this construction are very durable but not terribly contouring.
• Pocket Coils: Each pocket coil is encased in fabric and connected to other coils with strands of fabric. The design makes for good contouring, but thinner steel makes the coils less durable.

Shoppers should also pay attention to coil gauge, or thickness, which is measured on a scale from 18 (thinnest) to 12 (thickest). Lower gauge coils last longer and are firmer.

Memory foam and innerspring mattresses offer fairly different sleeping experiences. Sleepers tend to feel like they’re sleeping on top of an innerspring mattress, while memory foam lets sleepers sink into the mattress. Fans of innerspring say they have a supportive, even feel, and memory foam lovers appreciate the material’s conforming abilities.

Support

Innerspring mattresses tend to be fairly supportive because they create an even, flat surface, and coil construction plays a big role. Lower gauge coils are thicker and tend offer more support, and pocket and offset coils provide the best spinal alignment. Innersprings tend to sag over time, which compromises support, but they do provide the best support for individuals over 230 pounds.

Memory foam mattresses create a much more contoured sleep surface than innersprings, but that doesn’t mean they’re not supportive. Foam density indicates how well a memory foam mattress will support your weight. Look for something in the 4 to 5 pounds per cubic foot range. Also note that heavier individuals may not find adequate support in a memory foam mattress.

Conforming

Innerspring mattresses tend to be firmer than other mattress types and aren’t necessarily known for their conforming abilities. That’s because they don’t have very thick comfort layers that allow sleepers to sink into the mattress. For sleepers who like the feel of innerspring but want more contouring, consider a mattress with pocket coils. Each one moves independently of the others, so they can respond better to your body shape.

Contouring is what memory foam mattresses do best. The material responds to heat and pressure by conforming to a sleeper’s body, making an impression in the sleep surface that aligns the spine. That makes is especially well-suited for anyone with neck or back pain. Back and stomach sleepers should just make sure they don’t sink too low in a memory foam mattress to throw off spinal alignment.

Pressure Relief

Certain individuals are more prone to experiencing pressure points. Side sleepers, for instance, sometimes have pain near the shoulders and hips if they sleep on a mattress that’s too firm. Innerspring mattresses don’t offer the best pressure relief because they’re on the firmer side and have thinner comfort layers, though pocket coils and plush comfort layers do help.

Because of their ability to conform to the body, memory foam mattresses perform quite well when it comes to pressure relief. They allow heavier parts of the body to sink in comfortably while still providing support.

Good for Sex?

Responsiveness—how bouncy a mattress is—tends to make it better suited for sex. Most couples appreciate the responsiveness of innerspring, and they tend to be one of the best types of mattresses for sex. Memory foam doesn’t perform as well, and many couples report feeling like they’re fighting the mattress.

Temperature Regulation

If you tend to sleep hot, or your partner does, then temperature regulation is an important quality in a mattress. Because they have a fairly open construction, innerspring mattresses promote good airflow. They offer some of the best temperature regulation out of all mattress types.

Memory foam has a tendency to sleep hot. That’s because the mattress conforms to your body, trapping your body heat around you. It’s also a fairly dense material, so promotes less airflow than other materials.

Individuals with a new memory foam mattress often remark that it gives off a chemical smell. Memory foam tends to off-gas, or release chemical compounds into the air, when it’s first unpackaged. These compounds are in such a small concentration that they’re not harmful, but they may be unpleasant. You can always let your memory foam mattress air out in a well-ventilated room for a few days. If you’re especially sensitive to smell, innerspring may be a better option. Because they’re primarily composed of steel, innersprings tend not to off-gas.

Innerspring and memory foam mattresses tend to be similar in price, and they’re both usually less expensive than other mattress types. Still, price depends greatly on materials and construction. You can find a very cheap innerspring and a luxury memory foam mattress, and vice versa.

Coil type impacts the cost of innersprings to a large degree. Pocket coils tend to be the most expensive. Offset coils are mid-range and bonnell and continuous are the least expensive. By and large, innerspring mattresses are the cheapest on the market. Memory foam mattress cost depends a lot on foam density. Low-density is the cheapest and least durable, high-density costs the most.

Memory foam mattresses tend to have a longer lifespan—seven years on average—than innerspring, which last about five and a half years. For innersprings, non-tempered steel, typically found in pocket coils, is less durable than tempered. Similarly, low-gauge wire is more durable than high gauge, so bonnell and offset coils have the longest lifespan.

Density plays a big role in the longevity of a memory foam mattress. Low density doesn’t hold up as well in the long-term, but high-density foam doesn’t retain its shape as quickly after each sleep. Medium-density memory foam offers the best of both worlds.

A good warranty is important for both types of mattresses because they can be prone to sagging. Be sure your mattress warranty covers sagging. Understand to what depth sagging is covered and other details, like how to handle claims, mattress replacement, and what costs you’re expected to cover.

The comparison table highlights the pros and cons of innerspring and memory foam mattresses.

You can learn more about different memory foam and innerspring products by checking out these other excellent guides from Tuck:

• Best Memory Foam Mattresses
• Best Memory Foam Toppers
• Best Memory Foam Pillows
• Best Innerspring Mattresses
• Memory Foam versus Latex