Our sleep experts have been sleeping on mattresses for years — some members eight years at this point. Having tested around 350 beds from dozens of different mattress brands, our team has a good understanding of bed firmness levels. Even with our advanced ones testing processes and years of experience comparing hardness, our judgments have been purely subjective — until recently.
Built by CNET Labs technology experts Brian Adams, Lab Engineer, Jared Hanna, Technical Product Test Analyst, and Steve Conaway, CNET Labs Director, Our Property 9000 Mattress Breaker the device offers an objective way to determine the firmness level of mattresses.
This nimble machine was officially launched in July and has so far broken almost 100 beds. This number is increasing weekly as our experts continue to break down the beds currently in stock in our expansion mattress warehouse and the new mattresses we regularly receive for review.
Read more: We use technology to test beds: Hello on the 9000 mattress
Watch senior video producer Owen Poole explain how the mattress breaker works and why it's changed the way we test beds.
The process of breaking the mattress
On average, breaking each bed takes about thirty minutes. Moving the beds into our designated mattress breaking room and placing them on the platform takes some time. Once the bed is properly positioned and the machine is ready, we press “start” and wait between three and five minutes for the machine to do its magic and provide us with the objective level of firmness.
This “magic” happens when the powerful actuator arm pushes its pressure-sensitive plate down into the mattress until it reaches a predetermined amount of force, simulating body weight. The machine calculates firmness based on the distance the arm and plate have traveled in the mattress until they reach that amount of force, traveling further (or deeper) in softer beds and not as far in firmer beds.
With our proprietary programming software, we can change the amount of force applied to the bed to simulate different body weights, allowing us to see how the firmness will feel for lighter and heavier body types.
We can adjust the drive arm of the 9000 mattress to test multiple areas of each bed.
We can also adjust the location of the actuator arm. Moving the positioning of the drive above the bed allows us to test different areas of the mattress, which is essential to determine if the zoned support sections are actually softer or firmer as brands may claim.
Read more: Using Bed Testing Technology: Hello to the 9000 Mattress
Mattress Break Scores, Ranked by Firmness
Firmness is rated on a scale of 1 to 10, with 1 being the softest and 10 being the firmest.We use industry terms like “medium-soft” or “real firm” to describe it. The firmness ratings provided by the mattress breaker are provided from the perspective of an average person weighing between 150 and 230 pounds, but we also test and discuss how the firmness might feel to someone weighing above or below that range.
We break each bed at least three times, but often four or five (sometimes as many as six or seven), averaging those results to determine the final target hardness level. Of the nearly 100 beds we've broken to date, the average hardness level is 5.7, or just a hair above average.
The chart below shows the firmness levels of the beds we tested with the 9000 mattress, organized from softest to firmest.
On Nectar Lux Hybrid and Helix Midnight Core the mattresses were the softest, with firmness levels of 2.1 and 2.17, respectively. Such soft results are best suited for strict side sleepers who need maximum pressure relief for their shoulders and hips.
The Smasher 9000 mattress pushes the actuator arm into the bed.
To no one's surprise on our team, the extra tough side of Planck Company ranked the firmest of all, landing an impressive 9.5 out of 10 by the mattress reviewer — confirming that it's best for back and stomach sleepers looking for the most support possible from a mattress.
As we continue to test and break in beds, we predict that the average firmness level will remain between 5 and 6. Many mattress companies offer middle-of-the-road beds that can accommodate all sleeping positions and body types and offer a combination of pressure facilitation and support.
Read more: The best firm mattresses of 2024
What we learned about mattress firmness
Not to toot our own horns, but we will… Brands are also pretty accurate in how they rank the firmness of their mattresses.
For Bear Original mattress, the mattress breaker provided 7.6, 7.6 and 7.8 ratings for an overall average firmness rating of 7.65 out of 10, while Bear rounded it out at 7.1. While it's not exactly the same, it's close, given that we have different methods and means of evaluating and determining firmness — both rankings mean the mattress lands around the firm middle.
We always test the firmness of the mattress subjectively first, followed by its objective result.
It's important to remember that even when technology is used to find an objective level of hardness, hardness is still subjective at the end of the day. How one person perceives the firmness and feel of a bed may differ from another, depending on body type and weight. Our sleep team consists of members of different body types, weights and genders, which allows us to test each mattress from different perspectives and provide a comprehensive review of the bed.
Zoned support
Many mattresses have zonal support, meaning that different levels of firmness throughout the bed provide support and pressure relief where your body needs it most. It is intended to help keep the spine in neutral alignment throughout the night.
This is achieved by changing the construction of the bed, usually with slightly firmer foam or a layer of individually wrapped coils in the center for increased support for your torso and hips. The outer thirds are often slightly softer to provide pressure relief for the head and shoulders. An example is Available Classicwhich has an additional layer of thin memory foam in the central third of the bed.
The Smasher 9000 mattress proved that the brands claims of zonal support are generally true and accurate. Even if we don't necessarily feel the zoned support while lying on certain beds, a mattress cramping machine can confirm that different levels of firmness are present.
On Getting an Rx is a great example of this. Specifically designed for those with chronic back and joint pain, has a patented lumbar zone technology. This technology provides more support in the central third of the mattress, in order to keep your spine in neutral alignment. We moved the drive to test each third of the mattress and confirmed that to be true — the inner ranked around 6.1 out of 10, and the outer thirds were slightly softer, around 5.4 out of 10.
With the mattress breaking machine, we can test the firmness of different areas in zonal support mattresses like the Saatva Rx.
We had some interesting discoveries during testing
Like any technology, the 9000 mattress is not always 100% accurate. It may occasionally rank a bed higher or lower than we know it to be, and we always use our best judgment and discretion to determine why and if the score is lower than what its firmness really is. We've come across some interesting insights as we continue to work out all the kinks with the mattress breaker.
Mattresses with super unique construction, as they are Layla Hybridcan sometimes throw off the hardness rating provided by the breaker. We always investigate to determine the cause, and in this case, because the Layla Hybrid is flippable, the mattress base is soft when the firm side is up, which resulted in some funky results.
We also discovered beds with soft comfort layers or cushioning top pillows tend to achieve softer results than they are. This is because the trigger arm of the mattress breaker does not press as far into the layers of the mattress as in a bed without a pillow top, causing it to provide a result that is softer than it would feel for a real person lying on the entire bed. .
An example of this is Titan Plus Lux. In our testing, we found this bed to be medium firm, while the mattress breaker consistently gave us lower scores between 3 and 4, which would be medium soft. We know this is because of the soft quilted gel foam on top of the Titan Plus Luxe.
The Titan Plus Lux has a thick pillow top that slightly affected the mattress score.
Temperature affects the results of mattress breakage
When a bed (especially one with memory foam) is cold from being outside in cold weather or a room without heat, it will score higher (firmer). The bed can become more rigid when it reaches a certain threshold, as memory foam is sensitive to temperature fluctuations. Foam molecules become more tightly packed when cold, resulting in a firmer feel. Typically, memory foam beds feel best in between 68 and 72 degrees.
Read more: The foam in your mattress is important. Here's how it's done
Our sleep team knows this well. We are patient when unpacking memory foam mattresses from the cold delivery truck in the winter because they are much stiffer and firmer than they will be when they have had a chance to warm up and inflate properly. It's the same when you're lying on a memory foam bed in a cold room — it takes extra time for your body heat to warm up before the foam begins to respond properly, sinking and contouring around you.
The building that houses our mattress warehouse recently experienced heating problems, which meant that there was no heat in the rooms where we store, film and break beds. The resulting cooler room temperatures affected mattress crash scores for memory foam mattresses, causing them to rank higher than they should.
Watch us unbox the ultra-cool Casper Snow Max.
Why we use technology to test beds
Our sleep experts always provide detailed descriptions of the bed's firmness and feel in our reviews to help you decide if it's the right bed for you. These qualities are largely subjective. What the bed looks like will vary from person to person. We take turns dissecting the mattress' construction, gathering opinions on firmness levels from multiple CNET sleep experts with different body types and preferred sleeping positions because it's critical to test and review this feature from a wide range of perspectives.
Until CNET Labs created the 9000 Mattress Breaker, this was the only way we could test the firmness of a bed. Now, having an objective way to test and determine hardness complements our expert judgments and makes our reviews even more accurate by providing completely unbiased data. As a dedicated member of CNET's sleep team, the Smasher 9000 mattress will continue to test and analyze beds with us for the foreseeable future.
Read more: How CNET's sleep experts test mattresses