Understanding the Mattress Firmness Scale: A Comprehensive Guide

A good night’s sleep is essential for overall health and well-being. And as we get older, changes in our sleep can get in the way of us getting the rest we need. Mattress firmness can impact sleep quality and comfort, so choosing the right firmness level can help you sleep better.

“As chiropractors, we are always looking at new ways to help retain the health of our patients’ spines and improve their quality of life. Mattresses are one of the most significant variables we see in sleep quality and spinal health because the average person spends about a third of their life in bed,” said Shandy Grady, DC, a Denver-based chiropractor.

The mattress firmness scale, which ranges from very soft to extra-firm, can help you find a mattress that balances comfort and support for your body type, sleep position, and personal preference. A mattress that is too soft may cause the body to sink, which can lead to bad spinal alignment, while a mattress that is too firm can create pressure and discomfort. The mattress firmness scale provides a standard way to measure firmness, so we can make informed decisions about our bedding.

Mattress firmness scale explained

Mattress firmness refers to how soft or hard a mattress feels when lying on it. It affects the level of support and comfort a mattress provides, impacting sleep quality. The mattress firmness scale is a standardized tool that ranges from one to 10, with one being the softest and 10 being the firmest. This scale helps buyers compare the firmness levels of different mattresses, so it’s easier to find one that suits their specific needs.

The standard one-to-10 scale for mattress firmness ratings typically breaks down as follows:

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

A mattress that falls at the lower end of the scale will feel plush and allow the body to sink in more, while a mattress at the higher end will feel firmer and provide more rigid support.

Mattress firmness levels breakdown

Choosing the right mattress firmness can help you get a good night’s sleep, especially for adults with specific comfort and support needs. This breakdown describes each firmness level and its potential benefits. Contour, sinkage, support, and pressure relief are important considerations when choosing a mattress.

Extra soft (1–2 out of 10)
An extra-soft mattress will have an extremely plush feel with a lot of sinkage. A mattress with a firmness level less than three is rare and is generally considered too soft. Our Reviews Team has never found a mattress with a one to two firmness rating.

Soft (3–4 out of 10)
Soft mattresses have a plush feel with noticeable contouring. They should offer a gentle cradle for the body and provide pressure relief for side and lighter-weight (less than 130 pounds) sleepers. These mattresses are designed to cushion the body, making them an option for those who need a softer sleep surface. 

See what we recommend in our best soft mattress article.

Medium (5–6 out of 10)
Medium mattresses have a balanced feel with moderate contouring. They offer a mix of support and comfort that’s good for a wide range of sleepers and sleep positions. Mattresses in this range are a softer medium. 

True medium (6.5 out of 10)
A mattress rated 6.5 out of 10 is considered a “true medium” and is the industry standard. Medium-firm mattresses have a supportive feel with light contouring. They provide support while offering some cushioning, which is potentially good for back pain. Research shows that medium-firm mattresses are best for people with back pain. These mattresses are ideal for those needing a firmer surface to support their back and spine while providing a plush contour. This standard is considered the most popular type of mattress because it caters to many types of sleepers. 

See our recommendations in our best medium-firm mattress article.

Firm (7–8 out of 10)
Firm mattresses have a solid feel with minimal contouring. They offer a stable sleep surface with little sinkage and are often recommended for stomach and higher-weight (more than 250 pounds) sleepers. Firmer mattresses typically compress less under more weight, providing the support higher-weight sleepers need. Stomach sleepers also generally need a firmer mattress to keep the hips elevated and spine aligned. 

See our recommendations in our best firm mattress article.

Extra firm (9–10 out of 10)
Extra-firm mattresses have a rigid feel with little contouring. They provide maximum support and a flat sleep surface, good for those who prefer sleeping “on” rather than “in” their mattress. These mattresses typically appeal to higher-weight sleepers looking for extra support. 

Factors that affect firmness perception

While the mattress firmness scale provides a standard, each person’s experience of firmness can vary. Firmness is subjective based on personal preference, body type, and sleep position. What one person considers a medium-firm mattress might feel too soft or too firm to another. 

Body weight

Body weight impacts how a mattress feels. Higher-weight sleepers tend to perceive mattresses as softer because they sink deeper into the comfort layers, experiencing more contouring and less support. On the other hand, lighter-weight sleepers may find the same mattress firmer since they do not compress the materials as much, which results in less sinkage and more surface-level support. For instance, a mattress rated as medium-firm might feel soft to a person who weighs more than 250 pounds but firm to someone less than 130 pounds.

See our best mattresses for heavy people for recommendations.

Personal preference

Each person’s comfort needs and sleep habits are unique and affect how they experience a mattress’s firmness. Some prefer a softer mattress with a plush, hugging feel, while others might prefer a firmer surface with solid support and minimal contouring. Preferences can be influenced by sleep position, with side sleepers often needing a softer mattress to reduce pressure at the hip and shoulder and back or stomach sleepers needing firmer options for proper spinal alignment.

Firmness and sleeping positions

Your preferred sleep position often influences the right mattress firmness. Each sleep position requires different levels of support and contouring to maintain proper spinal alignment and ensure comfort. This section explores the best firmness levels for side, back, stomach, and combination sleepersⓘ People who sleep in more than one position throughout the night .

• Best firmness for side sleepers: Side sleepers typically benefit from a mattress that offers a lot of contouring and pressure relief. A softer mattress ranging from three to six on the firmness scale is ideal for this position. See our recommendations for the best mattress for side sleepers.

• Ideal firmness for back sleepers: Back sleepers need a mattress that provides balanced support and maintains the spine’s natural curve. Medium-to-medium-firm mattresses, typically rated between five and seven on the firmness scale, often work well for back sleepers. Learn more in our recommendations for the best mattress for back sleepers.

• Recommended firmness for stomach sleepers: Stomach sleepers typically require a firmer mattress to prevent their midsection from sinking too deeply, which can lead to back pain. A firmer mattress rated between seven and nine on the firmness scale is usually the best choice for this sleep position. Learn more in our roundup of the best mattresses for stomach sleepers.

• Best firmness for combination sleepers: Combination sleepers who switch between multiple sleep positions throughout the night need a mattress that offers a balance of comfort and support across different positions. A medium-to-medium-firm mattress, typically rated between five and seven on the firmness scale, is often ideal for combination sleepers. See our recommendations in our best mattress for combination sleepers article.

Choosing the right mattress firmness for you

Various factors influence your best firmness level, including health conditions, body type, and personal preferences. 

Considerations for different health conditions

For those with health conditions, like back pain or arthritis, choosing the right mattress firmness can impact sleep quality and comfort. Adults with back pain may benefit from medium-firm to firm mattresses, which provide enough support for proper spinal alignment. 

“A firmer surface will often feel better for those with back pain because it will distribute gravity and body weight evenly instead of creating pressure points around the heaviest parts of the body,” said Alyssa Lawrenson, DC, owner of Refined Chiropractic & Wellness in Parker, Colorado. 

On the other hand, those with arthritis may prefer a softer mattress that offers enhanced pressure relief to reduce joint pain and stiffness.

Here are our mattress recommendations based on specific health conditions:

• Best mattress for back pain
• Best mattress for arthritis
• Best mattress for sciatica
• Best mattress for hip pain
• Best mattress for shoulder pain
• Best mattress for fibromyalgia

Importance of pressure relief and support

When choosing a mattress, pressure relief and support are key. Pressure relief helps distribute body weight evenly, reducing stress on common pressure pointsⓘ The parts of the sleeper’s body that are in direct contact with the mattress, such as the backside, shoulder, hips, and ribcage . Support ensures the spine remains neutral to prevent discomfort and potential pain. A mattress that offers a good balance of pressure relief and support is ideal for all body types.

Firmness for couples with different preferences

Couples with different firmness preferences may find it challenging to choose a mattress that satisfies both parties. But a medium-firm mattress is often a good compromise. Beds with dual-firmness options, like a split queen or split king, can cater to people with different preferences. A split bed is two mattresses on a single frame, so each person can pick their preferred firmness. Another option is a bed with adjustable firmness like the Saatva Solaire, which you adjust with a remote. This mattress has 50 firmness settings and features separate air chambers on each side for queen- and king-size mattresses.

We offer recommendations in our best mattress for couples review.

Edge support in relation to firmness

Edge support is important, especially for adults with mobility issues who may need extra stability when getting in and out of bed. Firmer mattresses generally provide better edge support, which prevents the edges from sagging and offers a secure perimeter. This feature also increases the usable sleep surface and adds to the overall durability of the mattress.

Temperature regulation and firmness

Studies have shown that heat exposure increases wakefulness during sleep. While a mattress’s firmness has little to do with its cooling properties, certain types of mattresses generally promote better cooling. For example, a hybrid mattress made with both foam or latex and innersprings helps with airflow because air can pass through the coils better than through foam or denser materials. Hybrid mattresses tend to be medium or firm, with the innersprings providing firmer support. But foam mattresses made with cooling materials, like gel memory foam ⓘ Memory foam with small gel pods designed for cooling or copperⓘ Copper is a good conductor and can absorb and disperse body heat, helping to regulate body temperature. , can also provide good cooling. The bottom line is that you can find mattresses that provide good cooling in different materials and firmness levels. 

Testing mattress firmness

Testing mattress firmness is essential to find the best fit. Here are some tips for in-store testing and understanding sleep trials:

• In-store tips: When testing a mattress in-store, spend at least 10–15 minutes lying on the mattress in your usual sleeping position. If you’re a combination sleeper, be sure to try all of your preferred positions. Pay attention to how the mattress feels in terms of support and pressure relief. Don’t hesitate to ask questions about the materials and construction of the mattress. Don’t expect a mattress to become more comfortable over time. “If the bed is not comfortable in the store, it won’t be comfortable at home,” said Grady.
• Sleep trials: Most online mattress retailers offer sleep trials, which allow you to test the mattress at home for an extended period. The industry standard is 100 nights, but some brands offer up to a full year. Take advantage of these trials to ensure the mattress meets your comfort and support needs. 

“It’s impossible to figure out if a mattress will work for you unless you sleep on it for a minimum of one to two weeks. Find a place that offers free delivery and pick-up for returns with at least a 90-day trial period.” — Kevin Nelson, DC, a chiropractor at Advanced Regenerative Health in Colorado

Common misconceptions about mattress firmness

Understanding the truth behind mattress myths can help you make a more informed choice, so you can find the best mattress for you.

Softness doesn’t always mean lack of support

Another myth is that soft mattresses lack support. While it’s true that some very soft mattresses can cause too much sinkage, many modern soft mattresses are designed with quality materials and construction techniques to provide both plush comfort and good support. These mattresses can contour to the body while still maintaining spinal alignment. This is why it’s important to consider the overall design and quality of the mattress rather than assuming that if it’s soft, it lacks support.

The myth of ‘universal comfort’

The idea that there is a “universal comfort” mattress that suits everyone is a persistent myth in the mattress industry. In reality, comfort is highly subjective and varies from person to person based on body weight, sleep position, and personal preferences. While some mattresses are marketed as having universal appeal, always consider your own needs and test mattresses whenever possible. What works for one person may not be comfortable for another, so relying on the concept of universal comfort may be disappointing.

Bottom line 

Understanding how mattress firmness works can help you select a mattress that provides the right balance of comfort and support. Key considerations include your sleep position, body weight, preferences, and health conditions, like back pain or arthritis.

Remember, your idea of firmness may differ from someone else’s, so it’s important to test mattresses whenever possible and take advantage of the sleep trials many brands offer. Don’t be swayed by common misconceptions: Firmer isn’t always better for back pain, soft mattresses can still provide support, and there’s no one-size-fits-all solution for mattress comfort.

Additional sleep resources

• Best Mattress for Seniors
• Best Mattress
• Mattress Sizes Guide
• Best Sleeping Positions
• Tips for a Better Sleep

Have questions about this review? Email us at reviewsteam@ncoa.org.

Sources

1. Radwan A, et al. Effect of Different Mattress Designs on Promoting Sleep Quality, Pain Reduction, and Spinal Alignment in Adults With or Without Back Pain; Systematic Review of Controlled Trials. Sleep Health. December 2015. Found on the internet at https://www.sciencedirect.com/science/article/pii/S2352721815001400
2. Caggiari G, et al. What Type of Mattress Should be Chosen to Avoid Back Pain and Improve Sleep Quality? Review of the Literature. Journal of Orthopaedics and Traumatology. Dec. 8, 2021. Found on the internet at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8655046
3. Okamoto-Mizuno K and Mizuno K. Effects of Thermal Environment on Sleep and Circadian Rhythm. Journal of Physiological Anthropology. May 31, 2012. Found on the internet at  https://jphysiolanthropol.biomedcentral.com/articles/10.1186/1880-6805-31-14

Lauren Sherman Author

Lauren Sherman, M.S., is a health content writer with a master’s degree in human genetics from the University of Colorado Anschutz Medical Center, laboratory experience from National Jewish Health, and clinical experience from Children’s Hospital Colorado.

Suzanne Gorovoy Medical Reviewer

Suzanne Gorovoy is a clinical psychologist, behavioral sleep medicine specialist, and member of the Sleep and Health Research Program at the University of Arizona College of Medicine. She received her graduate degree in School Psychology from Teachers College at Columbia University, her PhD in Clinical Psychology from Case Western Reserve University, and completed a postdoctoral fellowship in Behavioral Sleep Medicine at the University of Arizona College of Medicine.