The Definitive Guide to Innerspring Mattresses
Just like a good pair of jeans, the innerspring mattress will never go out of style. First developed in the 1880s, the design was inspired by the shock-absorbing seat cushions made for horse-drawn carriages. By the 1930s, innerspring mattresses had become the most popular type of sleep surface, and they remain so today.
Of course, even classics have to adapt to changing times. (Let's just say we're thankful the era of low-rise jeans is over.) Because of recent improvements—think high-tech materials, improved designs, and manufacturing methods that limit motion transfer and squeakiness—today's innerspring mattress is better than ever.
If you're in the market for a new innerspring mattress, here's everything you need to know, from what's between the covers to how to assess quality to which type of sleepers it suits best.
What is an innerspring mattress?
An innerspring mattress takes its name from the metal support coils that form the core of the bed. Most innerspring mattresses today also contain layers made with other materials, such as memory foam and latex, for added comfort, performance, and durability. That essential quality of "springiness," though, is the innerspring mattress's defining characteristic.
What's inside an innerspring mattress?
There are a handful of components common to most innerspring mattresses. When comparing products, these are the key things to look for:
The type and construction of coils have everything to do with how an innerspring mattress feels, how long it lasts, and how much it costs. There are four main categories of coils:
- Bonnell: Also called "open" coils, these are the oldest and most basic type of mattress springs (remember those buggy seats?). Bonnell coils are shaped like an hourglass and often wired together to form a continuous unit. That makes them durable but not very good at controlling motion transfer. “This type of mattress is probably like the mattress you slept on as a child," says Bill Fish, certified sleep science coach and founder of the sleep website tuck.com.
- Offset coils: Like Bonnell coils, these are also hourglass in shape, "but the bottom of the coil is offset when compressed to create a bit of a hinging effect," Fish says. That hinging effect makes them better able to conform to the body's curves.
- Continuous coils: “Continuous wire coils are similar to offset coils but have several rows of singular wires molded into shapes of a circle," Fish explains. “While they may have a long lifespan, these coils don't provide the support that most sleepers require."
- Pocketed coils: Pocketed coils are individually encased in fabric, which means they can move independently and contour to the sleeper's body much better than open coils. “Because the coils are not physically attached to each other, they provide outstanding motion isolation, meaning your sleep partner will not feel any tossing and turning that may take place during the night," Fish says. Pocketed coils are standard on higher quality innerspring mattresses.
Other less important coil factors to consider: coil count and coil gauge. Higher coil counts used to be associated with better quality mattresses, but that's not the case today. The materials used in the mattress and the type of coils are much more important indicators of innerspring mattress quality. For example, an innerspring mattress could have a high coil count with springs made of low quality steel. A general rule is to look for a minimum of 400 coils in a queen-size bed; the average is around 700. Anything too much higher than that likely won't make a significant difference in comfort or support.
Coil gauge refers to the thickness of a coil. The higher the gauge number, the thinner and more flexible the spring. A higher gauge is a better option if you want a softer mattress, but a lower gauge usually lasts longer. Thicker springs are also a better choice if you're on the heavier side since they provide stronger support. A coil gauge in the range of 12 to 15 should ensure an innerspring mattress can provide good comfort, support, and durability.
There's a lot more to an innerspring mattress than just the springs. In fact, what goes on top of the coils—typically some combination of foam, padding, and sometimes even more coils—is just as important when it comes to how comfortably you'll sleep.
Depending on the number and type of layers, the mattress may be considered a "hybrid," which signals that it contains a coil support system along with another material, typically memory foam. When evaluating innerspring mattresses, these are the layers you're most likely to encounter:
- Comfort layer: The top layer of the mattress, intended to provide cushioning and pressure relief, the comfort layer is usually made from memory foam, latex, or another type of foam.
- Cooling materials: Because foams tend to trap body heat, some mattresses incorporate cooling technology (such as cooling gel or graphite) in the foam comfort layer.
- Comfort coils: Some innerspring mattresses (including the Saatva Classic) use "coil-on-coil" technology, which adds a second set of individually pocketed coils on top of the steel coil base. The thicker bottom coils provide a durable and stable support core, while the thinner top coils provide contouring for comfort and cut down on motion transfer.
- Pillow top: Yet another layer of cushioning on the top surface of the mattress. There are two types of pillow tops: Euro-style and standard. A conventional pillow top is sewn onto the top surface of the mattress, with a gap between the pillow top and the mattress itself. The padding of a Euro pillow top is inserted underneath the top cover of the mattress, flush with the mattress edges. In addition to giving the mattress a cleaner look, Euro pillow tops won't shift or lose shape the way a regular pillow top can.
- Cover: All of these layers and components come wrapped in an outer cover. For maximum sleep comfort, a mattress cover should be made of a material that is soft, breathable, and moisture-wicking.
The lumbar region of your back is located just above your hips. Lumbar support is crucial in order to preserve the natural curvature of the spine. Without it, your midsection (where most people carry their weight) will sink into the mattress and pull the spine out of alignment—a long-term recipe for back pain.
A mattress without lumbar support will also show signs of wear and tear more quickly. Look for an innerspring mattress with reinforcement in the center third section, such as denser foam or hidden steel wires, to support the added weight.
Proper edge support makes it possible to comfortably and safely use every inch of the bed, whether sitting on the edge to put on your socks or sleeping next to the edge when your partner (or your dog) crowds the space. Edge support also prevents sagging and provides more durability. An innerspring mattress with edge support will have a layer of foam or heavier coils around the perimeter to bolster its structure.
Learn More About Saatva's Innerspring Mattress
The benefits of sleeping on an innerspring mattress
There are a lot of reasons why you'd want to choose an innerspring mattress over another type of bed. Here are some of the biggest benefits of sleeping on an innerspring mattress:
- Innerspring mattresses are familiar. When you're making a purchase as important as the mattress you'll sleep on every night, sometimes sticking with what you know can give you peace of mind. Even if you opt for a newfangled hybrid, you can expect that "classic" innerspring mattress feel, with a bounce that cradles your weight but never lets you sink in too deeply.
- Innerspring mattresses sleep cool. If you tend to "sleep hot," an innerspring mattress is your best bet, as the space between coils allows plenty of air to circulate.
- Innerspring mattresses support a range of sleep styles. Whether you're a side sleeper, back sleeper, or stomach sleeper, you can sleep comfortably on an innerspring mattress. And if you tend to shift positions during the night, the inherent "springiness" makes it easy to move across the surface of the mattress. (It also make it easier to get out of bed, but we're not sure that's a good thing.)
- Innerspring mattresses are good for sex. The website sleeplikethedead.com rates innerspring and hybrids two of the best types of mattresses to get busy on, owing to the ease of movement noted above, and the natural bounce and responsiveness.
- Innerspring mattresses are cost-effective. In general, high-quality innerspring mattresses cost less than high-quality memory foam and latex beds. A high-quality innerspring mattress starts at about a thousand dollars. (Learn more about how much to pay for a quality mattress.)
- Innerspring mattresses are durable. Innerspring mattresses offer great bang for your buck. A well-made innerspring mattress can last from 10 to 15 years.
Take our quiz to find out which Saatva mattress is right for you.
The drawbacks of sleeping on an innerspring mattress
There are pros and cons to every type of mattress. An innerspring mattress may not be right for you if:
- You're easily disturbed: “If you have a sleep partner, any innerspring mattress that does not contain pocketed coils is going to have substandard motion isolation characteristics," says Fish. “If someone gets up to use the bathroom in the middle of the night, their partner is going to feel their movements."
- You have joint pain: For those with back pain or joint issues, you may find that other mattress types, like memory foam, provide you with more cushioning. “For someone with joint pain, an innerspring mattress will probably not have the conforming capabilities to cradle those pressure points," says Fish.
Who an innerspring mattress is ideal for
It's safe to say that one of the reasons innerspring mattresses have maintained their popularity throughout the years is that they support a wide range of sleep styles. Within the innerspring mattress category, look for these features depending on your preferred sleep position:
- If you're a side sleeper: Side sleepers tend to need a softer, or more "plush," innerspring mattress to cushion pressure points created by the shoulders and hips.
- If you're a back sleeper: Back sleepers do best on a medium firm innerspring mattress, though they can find comfort on a wide range of firmnesses. The most important consideration for a back sleeper is proper lumbar support, so hips don't sink too deeply.
- If you're a stomach sleeper: Stomach sleeping is generally considered the least healthy position, but stomach sleepers can be comfortable with the right firmness level—namely, firm enough to keep hips from sinking and causing the spine to bow unnaturally.
As far as body type goes, innerspring mattresses are ideal for those on the heavier side. “Larger sleepers are best suited for innerspring mattresses as they provided much-needed support," says Fish.
The right base for an innerspring mattress
Speaking of support, your mattress needs it too. An innerspring mattress is usually paired with a foundation (a.k.a. box spring) or base. The most important thing is that it has a sturdy surface underneath, to keep the mattress from sagging and prolong its life. (In fact, some mattress warranties require the use of a specific type of foundation, and anything else will void the warranty.)
In addition to the standard combination of a box spring and metal bed frame, innerspring mattresses are compatible with platform bases, slatted bases, and adjustable bases—though not every innerspring works with an adjustable base, so be sure to check before you make a purchase.
Learn More About Saatva's Adjustable Base
The fine print
If you've made it this far, we know you're serious about your innerspring mattress purchase. In addition to materials and construction, there's one more important set of criteria to review: policies around delivery, home trials, returns, and warranties. Before you hand over your credit card number, check out our Guide to Mattress Fine Print.
Here's how our innerspring mattress compares to others on the market: