Mattress Coils: Considerations When Purchasing a Mattress

Mattress Coils

How many coils should a good mattress have? After reading about the number of coils in a hybrid model you’re eyeing, this question probably passed through your mind. It’s a legitimate question to ask. If you’re shopping for an innerspring or a hybrid, this is one of the details you should know. But there’s more to find out. 

The first-tier factors to consider include construction and materials, firmness, cooling, motion isolation, etc. Under construction and materials, you can be more specific and focus on mattress coils. Gauges and types are two of the qualities to inspect on top of coil count. And this guide will walk you through the whole nine yards.

You’ll learn why pocket coils are all the rage these days. And why Bonnell coils have fallen out of grace. Is there a chance to revive the latter, or will we just let it rest in peace in spring heaven? Keep reading for the most interesting facts about mattress coils.

Interesting Facts About Mattress Coils

1. Steel Coil Springs Are Old

Even though innerspring types became popular in the 1930s, steel coil springs have been around since 1857. But they weren’t used in beds at the beginning. Instead, you’d find them in chair seats. By 1865, mattresses started sporting them. And they say the rest is history.

2. They Are Shock Absorbers

Do your kids love jumping up and down the bed (or do you)? Such sleeping spaces containing spring coils can absorb movements quite well. This is why, with a hybrid or innerspring, you get that addictive bouncy sensation. However, this also tends to wear out the mattress fast.

3. They Come In Different Types

We mentioned Bonnell coils earlier. You probably thought, “Oh, the coils have a name?” As far as we know, there are two names—the other one’s Marshall. But other types have more descriptive names. You can read about them under the Coil Types Section. Knowing which kind is found in a bed can help you choose the right fit for you.

4. Innerspring and Hybrid

Speaking of mattresses, you can find spring coils in innerspring and hybrids. The former is the first and more traditional kind. It is usually composed of a thin comfort layer and Bonnell coils. On the other hand, the latter is made of memory foam and/or other foam types and Marshall coils. You’ll learn more about their differences in the Innerspring vs Hybrid Section.

5. Tempered and Non-Tempered Coils

Tempered coils have been heated many times before they are cooled. This process allows them to retain their form and shape, making for a durable spring base for beds. Tempered ones are better than non-tempered ones in this regard. You can benefit from using the former, especially if you are on the heavier side.

Coil Gauges

When you talk about coil gauges, you’re referring to the thickness of the mattress coil. A low gauge indicates greater thickness. A higher one means less thickness. And the latter also tells you that the coil has a firm and stiff quality, contributing to the hard feel of the bed surface. Between 12 and 14, you should go for 12 for the bouncier, more durable option.

Anything from 13 or lower is considered ideal in the mattress industry. So from our example earlier, a 12-gauge spring system delivers firm support and stability to sleepers. At 14, the gauge offers a compromise but is still quite acceptable. However, you should not push beyond that to maximize the benefits of your hybrid or innerspring mattress.

Lower gauges have thicker wires, translating to a longer lifespan. These wear out more slowly than their high-gauge counterparts. So if you’re concerned about durability, coil gauge is the component to check out. While it can boost the strength of a bed, it isn’t recommended to reach the utmost end before shopping for a replacement.

Coil Count

Meanwhile, coil count is a reliable indicator of how long a mattress could last. It also determines the level of support provided to your body. It’s right to steer away from a low number. And with many other elements to inspect, the mattress industry has not come up with a minimum coil count.

We will try to give you an acceptable figure. Depending on the size, a full mattress should contain 300 coils, a queen mattress should sport at least 400 coils, and a king-size one should have at least 380 coils. If it goes way higher, though, the greater coil count does not guarantee that the bed will perform much better. The one with the minimum coil count may even produce higher coil density.

The maximum number can also be based on the mattress type. Is it an innerspring or a hybrid? An innerspring (Queen) can have between 400 and 900. The average coil count is 750.

Coil Types

Bonnell Coils

The first and oldest, Bonnell coil has been around for a long time. This spring system featured in the buggy seats of the 1800s. Its steel wire coils sport an hourglass shape, coupled with knotted, round tops. Forming an innerspring unit or a Bonnell unit, crosswire chemicals are used to link the coils together.

These days, Bonnell springs are chosen for their low price and availability. You can check out an innerspring in the low- to mid-range category and find this spring system inside. While it can absorb shock well, this material can transfer lots of motion. Skip this if you’re a light sleeper.

Offset Coils

Offset coils are also hourglass-shaped like Bonnell coins, from which they’re derived. But you can differentiate them by their top and bottom parts, which are flat or square. The ends of every two square ends are tied using helical wires to form the innerspring unit. This results in a hinging effect, making the unit respond individually to your body. In turn, it enhances the bed’s contouring properties.

Further, you can choose between knotted and unknotted offset coils. Knotted coils feel smoother and are more stable. Unknotted ones are springier and more responsive. Featuring a more complex construction than Bonnell, this coil type is in-demand among high-end mattress models.

Continuous Coils

Trusted mattress brand Serta popularized this type. But it was Leggett & Platt that created this spring system for the manufacturer. It was marketed as the Mira-coil. Still, continuous coils stuck because of the continuous wire that ties together its parts. The more common version has rows that run crosswise. But to increase the weight a mattress can support, some combine crosswise and lengthwise.

Like offset coils, continuous coils are highly responsive and flexible.

Marshall or Pocketed Coils

The current favorite among mattress-makers, Marshall coils have also caught the attention of consumers. You probably know them by terms like individually wrapped coils, independently encased coils, and pocket coils. This type is characterized by its barrel-shape and thin gauge. It’s also knotless, with units linked by wires then wrapped in a man-made, non-woven fabric.  

Instead of acting as a single unit, pocketed coils work independently. This allows them to carry more weight, produce a firmer surface, and isolate motion. They can be compressed, too, such as in the case of beds inboxes.

Innerspring vs Hybrid


Like we said, innerspring mattresses have been around since the 1900s. Steel coil springs make up the core of this mattress type. Its top and bottom layers are then filled with upholstery, usually polyurethane foam. You can measure the thickness of its core through the coil gauge. Based on what you’ve read about coil gauge so far, which is better: 12.5-gauge or 14-gauge coils?

Back in the day, Bonnell coils were preferred. But these days, you can find an innerspring with individually encased coils as well. Before you buy, make sure you know the model’s materials and performance.


Fiber, memory foam, latex, and specialized foam (gel-infused and other-element-infused) are the common choices for the upholstery of innerspring. You have a better chance of finding polyester or cotton than of scoring memory foam. Anything with more than 1.5 inches of the latter is considered a hybrid.


Innersprings are not just known for the springy sensation they give. They’re also great at promoting airflow, which helps keep you cool at night. Often, they also come at budget-friendly prices. And you have a variety of designs, sizes, and firmness levels to choose from. Every sleeper type is accommodated by this mattress type.


The cheapest type out there, innerspring is a good option for those in a tight budget. You can own one for as low as $700 or below. And the most you can spend, based on averages, is $1,200. That’s even less than the mid-range price average of hybrids. Take note that this pricing is applicable to queen sizes.

Read: 10 Best Innerspring Mattress in 2019


Hybrids combine two known mattress systems. Hence, the name. With this type, you get the best of innerspring and foam (usually memory foam). It brings together the springy feel of innerspring and the comfort, softness, and conformity of foam. You can distinguish it from its innerspring counterparts by the thickness of the comfort/top layer—1.5 inches and up.

Another important factor that differentiates it is the type of coil used. Independently pocketed coils are more commonly integrated into hybrid models. In fact, hybrids are considered the modern version of innerspring. This is due to their preference for the more advanced Marshall coil system.

Many online mattress brands offering all-foams have ventured into creating hybrids as well.


With a hybrid, you can enjoy the benefits of the different all-foam types. Of course, this depends on the materials found in its layers. You can experience the contouring comfort of memory foam, the breathable responsiveness of latex, and the support of polyurethane. But some manufacturers also packed their hybrid offerings with their proprietary foams. And these include materials infused with gel or copper and sporting adaptive or five-zoned features.


Top hybrids are preferred for their superior support and pressure relief. Both are present in the bed, with responsiveness complementing them. But any good-quality edition should provide benefits to back pain and sleep disorder sufferers. Couples and heavyweight sleepers are included as well. Models come in various thickness and firmness options, so you can easily find the right fit for you.

For those who can’t decide if they want an innerspring or an all-foam, this also opens up another area of consideration.


With the power combo of innerspring and all-foam, you can’t go wrong with a hybrid. Its prices are quite affordable. The mid-range average is between $1,500 and $2,000 for a queen version. With a variety of models to choose from, you can pick one that’s aligned with your budget. Lower-cost ones are in the less than $1,500 category. High-end options can go above $2,200.

Depending on the manufacturer, financing is available for eligible buyers. Check out the website of the brand or online store you’re purchasing from to be sure.

Read: 10 Best Hybrid Mattress


When shopping for a new mattress, one of the specific factors to look at is mattress coils. Understanding coil gauge, count, and type can help you choose the best model. And you better buy the right fit when it comes to spring models. As you’ve learned, they come with their respective advantages and disadvantages.

In general, Bonnell coils may not offer the highest quality. There’s a reason manufacturers have created pocketed coils and other types. However, some brands can balance design and performance using Bonnell. It’s like finding a needle in a haystack, though, with the myriad choices you have to deal with.

On this site, we’ve cut down the information to bite-size. You only see what you need. And when it comes to mattress coils, these are the essentials. Armed with this knowledge, you can confidently shop for an innerspring or hybrid. You can even tell someone how many coils should a good mattress has.

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