What is an Open Coil Mattress?

Posted by Sarah Harris - Head of Design and Development on 19th Oct 2022

What is an Open Coil Mattress?

Doubtless you’ll have slept on an open coil mattress at some point during your life. In fact, there’s a pretty good chance you snuggled down and slept on one just last night.

How do we know? We’re not mind readers. We just happen to know that despite a whole crop of ground-breaking new mattress types springing up (badumtish!) all over the mattress market during recent years, traditional innerspring, or coil, mattresses still continue to account for around 80% of all mattresses sold in the UK.

But what is an open coil mattress? How does it differ from a pocket sprung mattress? Does it differ? And what makes springs a better choice than memory foam or latex? In fact, now you mention it, is a coil mattress really better? 

And, of course, the big question: is this the mattress that’s going to help me sleep better?

You know that we know our beds. We eat, sleep and breathe mattress technology and sleep stats. So we’ve buckled down and done our research to bring you the ultimate guide to the open coil spring mattress.

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History of open coil mattresses

Ornately decorated period bedroom with thick elegant drapes above the bed and other drapes and aged pictures around the room.

Did you know that human beings have been sleeping on mattresses since around 3,000BC? That’s around the time that Ancient Troy was founded. Of course, back then, even Egyptian pharaohs and Greek Gods didn’t get the luxury of springs and breathable cotton toppers. Instead, aside from the Persians’ questionable goat skins filled with water idea (we don’t want to think about how that smelled), mattresses throughout history have been little more than straw, horsehair or leaf filled sacks. (1)

The first open coil mattress

1871. The Franco-Prussian war was raging. P.T. Barnum kicked off his inaugural circus shows. The very first exhibition of cats was held at Crystal Palace. And while those historically significant events were taking place, Mr. Westphal of Germany, an astronomer, was busy coming up with aground-breaking invention. An invention that would – eventually at least – revolutionise the way we sleep.

Inventing the mattress

With some time to kill between observing comets and trying to figure out the origins of cosmic rays, Westphal got to work designing the first coil spring mattress. His idea was based not only on the sprung armchairs gaining popularity at the time but also the iron spring bedsteads that had been in use since around 1850.

You’d think it would’ve been an instant hit, knowing what we do now, but sadly Westphal earned little money and almost no recognition for his smart invention. In fact, it would be another sixty years before the technology he pioneered was eventually adopted, long after Westphal’s death.

What is an open coil mattress?

Simply by Bensons Bliss Mattress

Simply by Bensons Bliss Mattress

Westphal’s early mattress wasn’t a million miles away from the design of the sprung mattresses we still sleep on to this very day.

Consisting of large, coiled metal springs which are linked together, open coil mattresses provide the bounce most of our bodies need for comfort. These springs took mattresses from dense, oversized pillow-type objects, full of lumps and bumps,to a much more comfortable proposition.

The springs in an open coil or traditional innerspring mattress don’t just give your bed that bounce, they’re also important for reliable firmness and support, ensuring you’re not sinking too far into your bed.

You see, the firmness of your mattress all depends on the number of coils packed into it(the average double contains 300 springs) and the gauge, or thickness, of those coils. Generally speaking, the lower gauge of the coil the firmer the bed,and the more coils present, the more support you’ll get.

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Changing mattress technology

As the years have passed, the build of the coil spring mattress has remained essentially unchanged. Many still feature similar fillings to those mattresses we adopted in the 1930s and 1940s too–wool, cotton or hair – while others contain silk, polyester fibre or foam. More recently, an increasing number of mattresses have been developed that combine springs with latex or memory foam, while many bring together several layers of different filling types to give you a wide variety of benefits.

Open coil vs pocket sprung: what’s the difference?

The open coil mattress is not the only type of innerspring mattress available. One of the most popular alternatives is the pocket sprung mattress. So, let’s dig a bit further into the difference between pocket sprung and open coil.

What is an open coil mattress? A mattress with coils ‘open’ to the mattress. And a pocket sprung mattress? Those coils are each kept inside individual pockets of fabric.

Though the essential difference between pocket sprung and open coil is in the presence (or absence) of that simple fabric pocket, there is a bit more to it than that:

  • Open coil mattresses are fitted with cojoined springs, every spring linked to its neighbour through a connecting wire. However, in a pocket sprung mattress each coil, though closely packed, is separate
  • Generally, an open coil mattress will contain fewer overall springs. While you’re likely to find an average of 300 springs in an open coil mattress (though this can bounce to 500), a pocket sprung mattress could contain many more. Take the Slumberland Eco Solutions 2200 Mattress with its 2,200 individually pocketed springs for example
  • Ordinarily, open coil mattresses feature an hourglass shaped coil (a Bonnell or offset coil) while in a pocket sprung mattress, the springs are straight

That’s the essential differences covered. Nowlet’s dig into the benefits of both mattress types…

Open coil mattresses: the pros

Simply by Bensons Smile Mattress

Simply by Bensons Smile Mattress

Open coil mattresses have a reputation for being lighter than their pocket sprung counterparts, although this isn’t always the case now that many contain additional layers, which can add bulk.

That said, simple open coil mattresses are still widely available, and their often-reduced weight may make turning a mattress easier for the less than musclebound. If mattress weight is of particular concern, we also recommend checking out memory foam mattresses.

Another tick in the box for open coil mattresses is that they can provide a cooler sleeping surface thanks to the airflow that can occur between the coils. This can make open coil a great choice for those who sleep hot. However, it’s important to do your research into the other materials used inside your mattress, any of which could reduce this effect.

Pocket spring mattresses: the pros

The chief advantage of a pocket sprung mattress is in those individual coils. Because each one moves independently, the mattress is able to supply differing support across the body, keeping you supported in just the places you most need it.

That same concept helps to minimise motion transfer too, helping to give you a restful night, even if your partner dreams of tapdancing.

It’s also the reason that these mattresses offer excellent durability. Most will last up to eight or ten years without a significant reduction in support and comfort.

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How are open coil mattresses made?

Although it might be relatively easy to choose between two mattress types, what can prove more of a challenge is knowing which exact mattress works from you. We can offer you all the help and advice you’ll need to choose your ideal mattress using sleeppro® technology and alongside that, for anyone who loves to know the nitty gritty details, here’s a bit of insight into how open coil mattresses are made.

Simply by Bensons mattress components diagram

We’ve answered the question ‘what is an open coil mattress?’ so you now have a pretty good idea of what’s lurking under that cotton covering. We’ve also uncovered the mysteries of the pocket sprung mattress and how it might differ from an open coil spring mattress.

However, there’s more than one layer to your mattress:

  • The Support Core: usually the coils of your mattress, although, of course, many mattresses will now contain a foam or latex core. Oh, and in an air bed this will, naturally, be made up of air chambers
  • The Transitional Layer: layered directly on top of the core of your mattress is what’s known as a transitional layer. This is a buffer between your body and the springs (because who likes a rogue coil digging into their back?) and it is often made of a relatively high-density foam to prevent sinking. Some mattresses feature a latex transitional layer while many will include a section of mini coils, usually wrapped in fabric or encased in foam. This supplies a pleasing amount of extra boiiiinnng!
  • The Comfort Layer: this layer will be the very first thing that catches your attention when trying out new mattresses in-store. The top layer of your mattress (and immediately below the cover), the comfort layer tends to be soft and encompassing. This is the luxury section of your bedand will tend to be deeper in softer mattresses and thinner in firmer mattresses to maintain contact with the good support beneath. Traditionally foam, wool or cotton, many modern mattresses now feature adaptive polyfoam, memory foam or latex. 

Open coil mattresses: the coils

The coils of an open spring mattress are usually made using highly durable tempered steel, exposed to repeated heating and cooling. This helps the coil to retain its shape and prolong its responsiveness for long lasting comfort.

Several types of coil shape are available but in an open coil mattress you’ll ordinarily find the hourglass shaped Bonnell coil or an offset coil. This is similarly shaped but with squared-off sides. While Bonnell coils are available in mattresses of any firmness rating, offset coils are commonly preferred for medium-to-firm beds. This is because they offer improved contouring and may reduce motion transfer.

Less commonly used are continuous coils. Though durable, these closely joined coils provide high levels of motion transfer and are therefore best accompanied by good, thick transitional and comfort layers.

Close up image of collection of springs piled tightly in a factory.

Which are the best open coil mattresses?

What is an open coil mattress? How is it made? Why choose an open coil mattress? With all of this information now at your fingertips (we hope), it’s time to go forth and choose your ideal mattress.

The mattress you pick is dependent on the firmness you prefer, the support you need and those little extras that will impact your comfort – we’re talking allergy prevention, cool tech and more.

Simple open coil spring mattress options

Sometimes simplicity is key and among our wide range of open coil mattresses you’ll find a variety of fuss-free sprung mattresses that just get on with the job of keeping you comfy at night.

The pocket sprung mattress for you

Head turned by pocket springs? We have more pocket sprung mattresses than you can shake a coil at.

Packed with ground-breaking mattress technology, the iGel Advance 1600 mattress offers 1600 pocket springs, cooling technology and more for long lasting reliable comfort.

Meanwhile the Slumberland Natural Solutions 2800 offers a supportive blend of pocket springs and mini springs along with natural fillings and plush quilting.

Choosing an open coil memory foam mattress

A move to memory foam doesn’t have to mean abandoning all the benefits of a sprung mattress. Many people love hybrid mattresses like the Westford Memory mattress, which combines a robust sprung core with a supportive memory layer for the best of both worlds.

The best open coil mattress for kids

Jaybe Simply Kids Open Coil Anti-Allergy Mattress

Jaybe Simply Kids Open Coil Anti-Allergy Mattress

A good mattress is vital for your child too and the support of sprung mattresses makes them great for growing bodies.

Kids can be sensitive to all sorts of allergens however, so we recommend choosing carefully if your little one is prone to sneezes and rashes. The Jay-Be Simply Kids OpenCoil foam-free mattress and the Jay-Be Simply Kids OpenCoil anti-allergy mattress are both excellent options for young children. Purotex® treated, these breathable mattresses minimise dust mite activity and help to regulate temperature, all while providing all the great support of innersprings.

Open coil mattresses at Bensons for Beds

We know how important choosing the perfect mattress is in ensuring you get the best night’s sleep possible for years to come. That’s why our knowledgeable, friendly team is on standby to help you whittle down your choices, no matter how long it takes.

With our smart SleepPro technology we can assist you in figuring out exactly what mattress firmness level you’ll need, and in just a few quick minutes at any one of our nationwide stores. And once you know whether you’re a firm Fred or a soft Stan we’ll take you through all your options, including the best open coil mattresses to suit your personalised requirements.

Any questions? Ready to order? Simply shop online, call 0808 144 6160 to speak to us, or pop into store.


  1. Who Invented the Bed? A Brief History on Beds and How They Evolved - Sleep Report


Coil Springs Explained - Bed Advice UK

Mattress Construction | Sleep Foundation

Mattress Coil Types | Sleep Foundation

Open Coil Vs. Pocket Spring Mattresses - Sleep Junkie

authors profile
Sarah Harris
Head of Design and Development
Sarah has worked at Bensons for Beds for 16 years. As Head of Design & Development, Sarah uses her wealth of experience in design to ensure that Bensons for Beds' products use the latest innovation in technologies to deliver maximum quality products that really help customers' everyday sleep issues.
Read more from Sarah