This CNET-only machine measures the firmness of the mattress. This is what we learned
Our sleep experts have been rolling in different beds and sleeping in different beds for years. After testing about 350 mattresses from dozens of brands, our team has a good idea of the sturdy level of mattresses. Even with our strategic testing process and extensive experience, our assessments remain subjective – until recently.
Our proprietary mattress Smasher 9000 Machine is brought to life by CNET Labs technologists Bryan Adams, Jared Hannah and Steve Conaway.
This neat device has smashed 100 beds and counted them. This number rises every week as our experts continue to test the beds currently stored in our spacious mattress warehouse and the new mattresses we often receive for review.
Read more: We use technology to test the bed: Say hello to the mattress Smasher 9000
Watch senior video producer Owen Poole explains how mattress crushers work and why it changed the way we test beds.
The process of mattress
It takes about thirty minutes to smash the bed. It takes some time to move the bed to our designated mattress crusher room and place the bed on the platform. Once the bed is properly positioned and the machine is ready, we make sure the program numbering of the connection is correct, click “Start” and wait a few minutes to get Smasher to do its magic and give us an objective level of firmness.
This “magic” occurs when a powerful actuator arm pushes its pressure-sensitive plate down into the mattress until it reaches a predetermined force, thus simulating the weight. The machine calculates firmness based on the distance the arms and plates enter the mattress until they reach that force, and then further (or deeper) into the softer bed, rather than into the firmer bed.
With our custom programming software, we can change the forces applied to the bed to simulate different weights, allowing us to understand the firmness of lighter, heavier body types.
We can adjust the execution arm of the mattress Smasher 9000 to test multiple areas of each bed.
We can also adjust the position of the actuator arm. Moving the actuator in the position on the bed allows us to test the various areas of the mattress, which helps us determine if the partition support is indeed softer or firmer, as the brand says.
Read more: Test bed using technology: Say hello to the mattress crusher 9000
Mattress crushing effect, firmly ranked
The firm levels are 1 to 10, with 1 being the softest and the most fixed is the strongest.We use industry terms like “medium” or “real company” to describe it. The mattress crusher provides a firmness score from the perspective of an average person with a weight between 150 and 230 pounds, but we also tested and discussed the firmness of someone above or below that range.
We will at least three times per bed, but usually four to five (sometimes up to six or seven) to get the average of these scores to determine the final objective stability level. So far, we have crushed the average firmness level in nearly 100 beds at 5.7, or just hair above the medium.
The following image shows the firmness of our 9000 crushed bed with the softest to the most solid tissue mattress.
According to Smasher, the Helix Sunset Luxe and Nectar Luxe hybrid mattresses are the softest, with firm levels of 2.1 and 2.2, respectively. Such soft scores are best suited for strict side sleepers, where they need to provide maximum pressure on shoulders and hips.
The mattress Smasher 9000 pushes the actuator arm into the bed.
Surprisingly, the Airweave Nagomi mattress was surprised by our team. In fact, it gets over 10 firm levels from mattress crushers. This unique super-fixed bed is built with ventilated machine fiber blocks, making it only suitable for rear sleepers seeking maximum support.
The next most sturdy mattress is also no surprise that the super-enterprise side of the board company landed in 9.8 of 10, with board company Luxe following behind.
As we continue to test and crush the bed, we expect the average firmness to remain between 5 and 6. Many mattress companies offer intermediate beds that can accommodate all sleeping positions and body types and provide a combination of stress relief and support.
Read more: The best solid mattresses of 2025
We have a firm understanding of the mattress
Not to get our own corners dirty, but we will… This new member of our testing confirmed that our team of sleep experts is very accurate when evaluating and ranking the hardness levels of the bed. Brands are also usually accurate in ranking the firmness of mattresses.
For the bear's original mattress, the mattress crusher offers scores of 7.6, 7.6 and 7.8, with an average firmness ranking of 7.65 out of 10, while the bear's 7.1. Although we have different methods and methods to evaluate and determine firmness, it is not exactly the same, but it is close and the two rankings mean mattresses land around medium companies.
We always subjectively test the mattress to be firm and then its target score.
It is important to remember that even if technology is used to find an objective firmness, fixation is still subjective at the end of the day. How one sees the firmness and feeling of the bed may differ from another, depending on body size and weight. Our sleep team consists of members of different body types, weights and genders, allowing us to test each mattress from a variety of angles and give a comprehensive review of the bed.
Partition support
Many mattresses have partitioned support, which means that the firmness throughout the bed is different and can provide support and pressure relief when most needed. It is designed to help keep the spine neutrally arranged throughout the night.
This is achieved by changing the structure of the bed, usually by having a slightly firm foam in the center or a separate layer of coils wrapped in it to enhance support to the torso and hips. The external third is usually slightly soft and can provide pressure relief to your head and shoulders. An example is the Saatva Classic, which has additional thin memory foam on the third floor of the bed.
Mattress Smasher 9000 proves that brand claims about partition support are often true and accurate. Even if we don’t necessarily feel the support of the partition when lying on certain beds, the mattress crusher can confirm that there are different firmnesses.
The Saatva RX is a great example. It is designed specifically for people suffering from chronic back and joint pain, with patented belt technology. This technology provides more support in the center of a third of the mattress and is designed to keep your spine neutral. We moved the actuator to test every third of the mattress and confirmed that it was correct – the inner ranks around 10 points, while the outer 3 is slightly softer, about 10 points.
With the help of a mattress crusher, we can test the firmness of each area in a mattress with partition support, such as the Saatva RX.
Interesting findings we found during the testing process
Like any technology, the Smasher 9000 is not always 100% accurate. It may occasionally rank higher or lower than what we know of, and we always use our best judgment and discretion to determine why and whether it stands out from the true meaning of its rating of firmness. We encountered some interesting insights as we continued to figure out any tangles with the mattress crusher.
Mattresses with super unique construction, such as the Layla Hybrid, sometimes throw away the firmness score Smasher offers. We always investigate to determine the cause, in this case, since the Layla hybrid is reversible, the bottom of the mattress is soft when the firm side is upward, which leads to some funky scores.
We also found that beds with soft comfort layers or cushioned pillows tend to be taller than previous ones. This is because the execution arm of the mattress crusher does not press down into the mattress layer like on the bed without a pillow top, which makes it provide a softer score than the real person on the bed.
An example is the Titan Plus Luxe. In our tests we found that the bed was in medium condition, and the mattress crusher always gave us a lower score of 3 to 4, which would be moderate. We know this is because of the soft stitching gel foam top on the Titan Plus Luxe.
Titan Plus Luxe's pillow top slightly affected the mattress Smasher's score.
Temperature will affect the results of the mattress crusher
It will score higher (stronger) when the bed (especially one with memory foam) is cold outside a room with no heat. When the bed reaches a certain threshold, the bed may become more rigid because memory foam is sensitive to temperature fluctuations. When cold, the foam molecules become tighter, creating a more difficult feeling. Generally, memory foam beds feel best between 68 and 72 degrees.
Read more: Foam in mattresses are important. This is how it is made
Our sleep team knows it very well. We are patient when we take apart memory foam mattresses from cold delivery trucks in the winter because they are stiff and sturdy than they have the chance to warm up and properly swell. The same thing happens when lying on a bed of memory foam in a cold room – your body heat takes extra time to warm up and sink and contour around you before the foam begins to react properly.
Our mattress warehouse building has recently encountered heating issues, which means there is no heat in the rooms where we store, film and crush beds. The resulting cooling chamber temperature affects the mattress crusher scores of memory foam mattresses, causing them to rank higher than they should.
Watch us take apart the extremely cold Casper snow.
Why do we use technology to test beds
Our sleep experts always give a deep description of the firmness of the bed and feel it in our reviews to help you determine if it’s right for you. These qualities are largely subjective. The bed feels different between people. We take turns lying and dissecting the mattress’s construction, gathering opinions from multiple CNET sleep experts on different body types and preferred sleep locations, as it is crucial to test and review this trait from a broad perspective.
Before creating the mattress Smasher 9000 in CNET Labs, it was the only way we could test the beds to be hard. Now, there is an objective way to test and determine firmness complement our expert evaluations and to be more precise by providing completely unbiased data. As a dedicated member of the CNET Sleep Team, the Mattress Smasher 9000 will continue to test and analyze the rest of us for the foreseeable future.
Read more: How CNET's sleep experts test mattresses
