Product Testing Methodology

At Sleep Doctor, our team personally tests every product that appears in our guides, reviews, and comparison pages. To evaluate products fairly and accurately, we follow a comprehensive testing methodology that incorporates a wide range of performance factors. Our team uses a unique set of performance criteria for each type of product, allowing us to make specific considerations for mattresses, pillows, sheets, bed frames, and other product categories.

Below, we’ll break down our rating system for mattresses to give you an idea of how this process works for all products we test in our lab. We’ll dive into each performance category in detail to help you understand the most important factors when choosing a new mattress. First, let’s introduce our sleep expert team and product testing philosophy.

Hands-On Research

Our hands-on research integrates a multitude of individual tests, allowing us to gain a holistic view of each product we evaluate. We physically test mattresses by lying down on them, getting on and off of them, and sitting along their edges. Additionally, we rely on technological tools for certain performance categories. These include body-mapping tools to measure pressure buildup, thermometers, and VOC detectors to evaluate off-gassing levels.

These detailed analyses allow us to generate accurate ratings. We believe these ratings go beyond information from manufacturers, and can help guide you toward deciding which sleep products are best for you. Every product we recommend has undergone a complete round of tests.

Our Product Testers

We’ve found both body weight and sleep position significantly influence which mattresses feel most comfortable. A side sleeper who weighs less than 130 pounds will likely prefer a softer, more adaptive mattress that cushions their body and alleviates pressure along the spine. On the other hand, a back or stomach sleeper weighing more than 230 pounds probably needs a strong, supportive mattress that won’t sink too much around the midsection.

For this reason, the testing team we’ve assembled is made up of side, back, stomach, and combination sleepers with a wide range of body types. This commitment to diversity ensures our ratings and recommendations are inclusive of all sleepers regardless of what they weigh or how they sleep.  

Mattress Ratings

Our mattress ratings take several factors into account. Each performance category entails multiple tests. Based on the outcomes of these tests, we assign ratings using a five-point scale:

• 1 – Poor
• 2 – Fair
• 3 – Good
• 4 – Very Good
• 5 – Excellent

Since findings can be subjective, our entire team takes part in the testing process to ensure objective, bias-free results. Below, we outline our major testing criteria for mattresses and how you can incorporate these factors into your search for the best mattress.

Firmness

We use the term firmness to describe how soft or firm a mattress feels. Firmness is measured using a 10-point scale, with 1 as the softest and 10 as the firmest. We’ve found most mattresses sold today fall between a 3 (soft) and 8 (firm) on this scale.

Firmness is directly tied to contouring, or how closely a mattress “hugs” your body. Softer mattresses contour deeply, while firmer models contour very little. To determine the firmness level of a mattress, our testers take turns lying on the surface to measure how closely the surface contours. We also use weights to measure compression.

Our 10-point firmness scale breaks down as follows:

• 1-2: Extra soft
• 3: Soft
• 4: Medium Soft
• 5: Medium
• 6: Medium Firm
• 7-8: Firm
• 9-10: Extra Firm

We often make mattress recommendations based on firmness, but keep in mind that firmness preferences are highly subjective. For instance, our findings show most side sleepers prefer softer mattresses than back or stomach sleepers. This should not be interpreted as us saying all side sleepers enjoy softer beds, but rather a recommendation based on the general consensus of side sleepers.

Sleeping Positions

The three standard sleeping positions are side, back, and stomach. “Combination sleeping” refers to people who switch between two or even all three of these positions during the course of a single night. Side sleepers typically need extra cushioning to cradle their shoulders and hips, as these two areas tend to experience pressure buildup. For side and back sleepers, extra reinforcement around the midsection helps maintain an even surface and prevent uncomfortable sinkage.

When testing each mattress, we’ll call upon team members belonging to the side, back, stomach, and combination categories. In addition to lying on the mattress to evaluate how comfortable it feels, they’ll perform various tests using their preferred position. Based on their feedback for the different performance categories, we’ll add up the results to generate an overall score for that position.

However, position is not the only sleeper factor we consider. Your body weight plays an equally important role in how comfortable a mattress feels. 

Sleeper Weight

When you lie on a mattress, the weight of your body compresses the comfort and support layers. Excessive compression can cause you to sink deeply into the mattress, which may lead to uneven spinal alignment and pressure points in the neck, shoulders, lower back, and hips. On the other hand, a mattress that feels too stiff may also seem uncomfortable because it lacks the cushioning to reduce aches and pains in these areas.

Based on findings during our tests, we use three categories when discussing sleeper weight.

• Less than 130 pounds: Sleepers in this range don’t compress their mattress very much, allowing them to lie on the surface without sinking too much. These individuals typically prefer mattresses that fall between soft (3) and medium (5), ensuring ample cushioning and even support.
• 130 to 230 pounds: Sleepers in this category often find balanced mattresses most comfortable, so medium (5) to medium firm (6) is usually the sweet spot. A mattress with moderate cushioning and a strong support system to push back against compression should be ideal for most people between 130 and 230 pounds.
• More than 230 pounds: We’ve found that people in this weight group usually need a mattress that falls between medium firm (6) and firm (8). These models usually have robust support cores to stabilize the sleep surface, and comfort layers that provide very little contouring.

These general observations are based on results of our hands-on tests, and they may not apply to you. We encourage all readers to take full advantage of sleep trials when choosing a mattress. These testing periods allow you to sleep on a new mattress for at least three months, giving you plenty of time to decide whether it feels too soft, too firm, or just right. If you aren’t satisfied, you can return the mattress for a refund.

Motion Isolation

When you change sleep positions or get in and out of bed, this movement can transfer to the other side of the mattress. If the transfer is substantial enough, this can cause your sleep partner to wake up. We’ve found that softer mattresses with thick foam layers isolate the most motion because they respond slowly to movement. Beds with latex layers and thick springs tend to be much bouncier, creating more transfer — often to a disruptive degree.

We evaluate motion isolation with a series of tests, beginning with two testers lying side by side on the mattress. One person changes positions while the other feels for transfer on their side, then they switch roles. We then drop kettlebells onto one side of the mattress while a tester on the other side feels for movement. Our SensorTag technology, which is similar to a seismograph, measures waves of movement on the surface. Lastly, we place a glass of water on the mattress next to a tester, then record whether the tester’s movement causes the water to spill or the glass remains upright despite motion elsewhere on the surface. 

Edge Support

The perimeter of your mattress is a key feature that is often overlooked. If the perimeter lacks adequate support, you may not feel secure lying close to the edges of your mattress, which leaves you confined to the middle of the bed. This can also cause sinkage that makes it more difficult to get in and out of bed. Many mattresses made today feature thick coils or foam rails along the perimeter to create extra stability.

Our testers evaluate edge support by taking turns lying and sitting along the mattress perimeter. We’ll mimic everyday movements like changing sleep positions, tying our shoes while sitting on the mattress, and getting in and out of bed. Throughout this process, each tester records how stable the perimeter feels, and whether or not they sink deeply.  

Sex

While most of our hands-on tests focus on sleep, we also take sex into account when evaluating mattresses. We’ve found the majority of couples prefer responsive, bouncy mattresses for sex. Mattresses that contour closely often excel at motion isolation and pressure relief, but they can also hinder movement during sex and cause excessive sinkage.

To generate ratings for sex, we essentially look at how the mattress performs in other testing categories. A stable perimeter is needed to ensure couples can use the entire mattress for sex, while the surface should push back against weight to allow for easy position changes. Therefore, edge support and ease of movement are directly tied to performance for sex. Temperature control is also key to keeping couples comfortable during sex. Lastly, we record how much noise a mattress makes when compressed. A mattress with creaky coils or other loud components may not provide the desired level of discretion during sex.  

Temperature Neutrality

A comfortable temperature is essential for a good night’s rest. If you feel too warm in bed, this can disrupt your sleep and negatively impact your overall sleep quality. For this reason, many people need a mattress with cooling components that promote air circulation, resist heat retention, and wick moisture away from the body. Examples include breathable cover materials, ventilated foam and latex layers, and coil systems that allow for airflow throughout the interior.

We evaluate temperature control using two separate tests. First, we heat a water bottle and place it on the mattress surface. After 15 minutes, we measure the temperature of the mattress directly beneath the spot where we placed the bottle, as well as surrounding areas. Once this process has concluded, our testers take turns lying on the mattress for 5 minutes in each sleep position to check for heat retention. 

Durability

The average mattress performs for six to eight years before it needs to be replaced. Quality materials often strongly indicate better durability. High-density foams, organic latex, and thick or zoned coils can help ensure a mattress will hold up well over time without developing deep surface indentations, trenching in the middle, or sagging along the edges.

The durability of a new mattress can be difficult to predict. For this reason, our durability ratings are educated estimates based on the quality of materials and design. We’ve found that firmer mattresses don’t compress or develop impressions as easily as softer models. Additionally, all-latex mattresses and latex hybrids tend to last longer because latex is a more resilient material than polyfoam or memory foam. 

Pressure Relief

You may notice sharp pressure points if certain areas of your body sink more deeply into a mattress than others. The shoulders, lower back, and hips are especially vulnerable to pressure because people tend to carry more weight around their midsections, causing the torso and waist to dig in more than the head and legs. Many of the best mattresses for pressure relief feature zoned layers that feel firmer and more supportive around the midsection, and softer elsewhere. This helps ensure an even surface from head to toe.

We test pressure relief using a body-mapping pad. Each tester lies on the pad, and we observe a visual display that shows areas of the body that are sinking somewhat deeply into the mattress. Our testers also lie on the mattress in different positions to see if they notice excessive sinkage. In our testing experience, softer mattresses with thick foam layers provide the best cushioning to reduce pressure. We’ve also found side sleepers are more vulnerable to pressure because this position places an undue amount of weight on the shoulder and hip resting on the mattress.

Off-Gassing

Off-gassing refers to the “new mattress smell” many people notice after unboxing their new bed. The most pungent odors are associated with volatile organic compounds (VOCs) released by synthetic foam. While mostly harmless, VOCs can emit a chemical odor many liken to plastic. Latex also has an initial rubber-like smell. Mattresses purchased online tend to emit particularly strong odors because they are vacuum-sealed for shipping, and this essentially locks in the off-gassing smells.

Our off-gassing tests consist of several smell tests conducted over a 24-hour period after unboxing the mattress. We’ll record how strong the smell is up close, as well as from a distance, and whether the intensity of the smells decreases during the first 24 hours. We also use a meter to measure the concentration of VOCs in the air before and after the unboxing takes place.

We’ve found that most mattresses release off-gassing odor for no longer than 72 hours, and many stop producing any odor within the first 24 hours. Placing your new mattress in a well-ventilated room for the first day or two after unboxing can mitigate this issue.

Ease of Movement

Lastly, we conduct ease of movement tests to see how easy it is to get on and off the mattress. Firmer mattresses with responsive, bouncy layers are usually easier to move across than those with softer, more adaptive layers. Coil support cores can also help you move on a mattress by creating strong pushback against your weight. Your own weight is another important factor. People who weigh less than 130 pounds tend to have an easier time moving on a mattress compared to individuals who weigh more.

To evaluate a mattress for ease of movement, our testers take turns getting on and off the bed. They also lie in different positions, noting how much the mattress sinks as they roll onto their side, back, and stomach. We also place kettlebells in the middle of a mattress, then record how long the top layers take to regain their original shape. Quick shape recovery indicates a responsive layer that promotes easier movement, while slow recovery may mean you’ll have a harder time moving on the mattress.