Do I Need a Soft or Firm Mattress?

Whether you need a ‘soft’ or ‘firm’ mattress will ultimately depend on your body, budget, and personal preferences. The right firmness level for a given sleeper varies by height, weight, and sleep position. Additionally, mattress firmness is often linked to pricing and performance factors like durability and temperature neutrality. Read on to learn more about finding a mattress with the right firmness level for you and your sleep partner.

Why Is Firmness Important?

A mattress with the right firmness level will provide adequate support and alleviate pressure points throughout the sleeper’s body. Mattresses that feel too firm or not firm enough can create joint discomfort, back and shoulder pain, and exacerbate pressure points.

How soft or firm a mattress feels will largely depend on how the comfort layer (or comfort system) is constructed, as well as its overall thickness. The comfort layer is defined as the body-cushioning system that forms the topmost part of the mattress, and its composition will determine how closely the mattress conforms to a sleeper’s body. Common comfort layer components include polyfoam, memory foam, latex, and/or steel microcoils, as well as the mattress cover. Some mattresses have a single-layer comfort system, while others may have as many as four or five individual layers in the comfort system.

Firmness is also tied to bodily support, although it’s important to differentiate between these two terms: firmness refers to how a mattress feels as soon as a sleeper lies down, whereas support refers to how a mattress aligns the sleeper’s spine and relieves pressure throughout the night. Mattresses that are too firm for a sleeper offer too much head, neck, and shoulder support; this can cause unnecessary pain and pressure. On the other hand, mattresses that are not firm enough may not provide enough support — and, as a result, may lead to comparable levels of physical discomfort.

Other factors can be used to evaluate firmness in different mattress types. In innerspring mattresses, the gauge (or thickness) of steel coil and other metal components can affect overall firmness. In mattresses made entirely of foam or latex, firmness is linked to a measurement known as indentation load deflection (or ILD). ILD refers to how much weight is needed to indent a sleep surface by 25%; mattresses with low ILD ratings are not as firm and require less weight for indentation, while mattresses with high ILD ratings are firmer and require more weight.

Due to the wide range of firmness preferences among individual sleepers, many mattress manufacturers offer models with multiple firmness options. Additionally, some mattresses are available in ‘dual firmness’ or ‘split firmness’ designs that feature different firmness settings on both sides of the top surface; these models are geared toward couples with differing firmness preferences. Other ‘flippable’ models feature different firmness ratings on both the top and bottom surfaces, and can be rotated at will.

How Is Firmness Measured?

At, we rate mattresses using the following 1-10 firmness scale:

  • 1 (Very Soft): An extremely plush sleep surface that sinks deeply beneath a sleeper’s body.
  • 2-3 (Soft): A very plush surface that conforms closely and sinks somewhat deeply.
  • 4 (Medium Soft): A plush surface with adequate conforming and minimal sinking.
  • 5 (Medium): An even balance of firmness and conforming with little sinking.
  • 6 (Medium Firm): A low-conforming surface with very little (if any) sinking.
  • 7-8 (Firm): A sufficiently firm surface that conforms to a degree without any sinking.
  • 9-10 (Very Firm): An extremely hard surface with no conforming or sinking.

It’s important to note that mattresses with firmness ratings of ‘1’, ‘9’, or ’10’ are quite rare because the vast majority of sleepers prefer surfaces with firmness ratings of 2 to 8. According to our feedback, the most popular firmness rating among all sleepers is ‘6 to 6.5’, which is considered ‘Medium Firm’.

Firmness and Sleeper Type

Body weight and sleep position are arguably the two most important factors for determining the right mattress firmness.

People with below-average weights generally feel more on mattress with lower firmness ratings; if the mattress is too firm, then they may not weigh enough to feel any conforming or pressure relief. On the other hand, people who weigh more than 230 pounds may experience uncomfortable sinking on mattresses with low firmness ratings.

Sleep position is key because it determines which areas of the body need more cushioning and support.

  • Back sleepers require spinal and lower back support to prevent pain and discomfort.
  • Side sleepers have vulnerable pressure points at the shoulders and hips, and also require neck support for proper spinal alignment.
  • Stomach sleepers generally need firmer mattresses to adequately support their hips and prevent uncomfortable sinking; most physicians do not recommend stomach sleeping due to the high risk of discomfort and pressure.

As a result, a side-sleeping individual who weighs 150 pounds will react quite differently to the feel of a mattress than a back- or stomach-sleeper who weighs 300 pounds. Additional factors include the sleeper’s shoulder, waist, and hip measurements. Using customer satisfaction reports, the table below features the most popular firmness rating for individuals with different weights and sleep positions:

Weight Group Sleep Position Optimal Firmness Range
Less than 130 Pounds (Below Average) Side Medium Soft to Medium
Back Medium Soft to Medium Firm
Stomach Medium Soft to Medium Firm
130 to 230 Pounds (Average) Side Medium Soft to Medium
Back Medium to Firm
Stomach Medium to Medium Firm
More than 230 Pounds (Above Average) Side Medium to Medium Firm
Back Medium Firm to Firm
Stomach Medium Firm to Firm

Firmness and Mattress Price

Although mattress price-points vary from brand to brand, models with low firmness ratings (1 to 3) tend to be the most expensive due to extra padding layers that make the comfort system feel exceptionally soft. Additionally, high-end materials like Talalay latex and gel memory foam tend to produce comfort systems with the lowest firmness ratings. Alternatively, firmer mattresses feature less padding and are usually cheaper by comparison.

Firmness and Mattress Performance

The firmness rating may be used to determine how a mattress will perform in the long run. Performance factors tied to mattress firmness include the following:

  • Durability: Mattresses with low firmness ratings — particularly innersprings — tend to be the least durable due to premature sagging and indentations in their relatively soft sleep surfaces. Firmer mattresses are less susceptible to this type of degradation, and their average lifespan is significantly longer.
  • Pain/Pressure Relief: Mattresses with mid-level firmness ratings (4 to 6) tend to alleviate the most bodily pain and pressure, since they are designed to offer a balance of comfort and support. Models that are too firm or not firm enough provide less pain and pressure relief by comparison.
  • Smell: Off-gassing odor is an issue for most mattresses, but mattresses with low firmness ratings (1 to 3) tend to produce stronger, longer-lasting smells because they have thicker foam layers; off-gassing is a major complaint among foam mattress owners. Firmer mattresses, on the other hand, generally contain lower amounts of foam and, as a result, produce less odor.
  • Temperature Neutrality: Medium Firm and Firm mattresses typically retain less body heat and sleep somewhat cool as a result, while mattresses with lower firmness ratings usually sleep warmer. However, temperature neutrality is more closely linked to mattress type; innersprings and hybrids tend to retain less body heat than foam and latex models.
  • Sex: According to customer reviews, mattresses with mid-level firmness ratings are best for sex because they are sufficiently responsive without causing too much sinkage. Mattresses with lower firmness ratings are also responsive enough for sex but sinkage is an issue for some, while firmer mattresses offer little to no responsiveness and may lead to discomfort during sex.
  • Ease of Moving/Maintaining: Mattresses with low firmness ratings are usually heavier, and need to be rotated more often, than mattresses with higher firmness ratings.

The table below features a summary of pricing and performance expectations for mattresses with different firmness ratings.

Category 1-3 Firmness (Soft) 4-6 Firmness (Medium) 7-10 Firmness (Firm)
Price Most Expensive Affordable Most Affordable
Durability Poor to Fair Fair to Good Good to Very Good
Pain/Pressure Relief Poor to Fair Good to Very Good Poor to Fair
Smell Poor to Fair Fair to Good Good to Very Good
Temperature Neutrality Poor to Fair Fair to Good Good to Very Good
Sex Good to Very Good Very Good to Excellent Poor to Fair
Ease of Moving/Maintaining Poor to Fair Fair to Good Good to Very Good

Firmness and Pillow Loft

Pillow thickness can greatly affect the feel of a mattress. The thickness of a pillow is measured using the term ‘loft’. Low-loft pillows measure less than three inches thick, medium-loft pillows measure three to five inches thick, and high-loft pillows measure more than five inches thick. A good rule-of-thumb when choosing pillows for a mattress: the lower the firmness rating, the lower the pillow loft. The table below features a detailed breakdown of the optimal pillow loft for different firmness ratings:

Firmness Rating Low-Loft Pillow Medium-Loft Pillow High-Loft Pillow
1 to 3 (Soft) Very Good Fair to Good Poor
4 to 6 (Medium) Fair to Good Very Good Fair to Good
7 to 10 (Firm) Poor Fair to Good Very Good

Buying Tips

Many mattress manufacturers list a firmness rating with different models. If this information is not available online for a particular model and you are unable to test out the mattress in person, we strongly recommend reaching out to that company’s customer service division to inquire about its firmness level.

Many online-only mattress brands offer sleep trials for new customers. These trials are typically 30 to 90 nights in length; customers have the option of returning their mattress for a full or partial refund before the trial period ends. In some cases, customers may be able to exchange their mattress for a different model — but it is important to read the fine print, since some brands do not allow customers to exchange their mattress for a model with a different firmness level.

Additionally, most companies will not honor warranty claims for customers who are dissatisfied with the firmness level of their mattress, or whose comfort preferences have changed since they made their original purchase. Unless the mattress shows another type of defect covered under the warranty (such as deep indentations or protruding wires), mattress owners will likely be unable to replace their mattress for a model with a different firmness rating.

Mattress Firmness Checklist

Before purchasing a mattress, here are a few firmness-oriented considerations to make:

  • What is your mattress budget? Mattresses with low firmness ratings tend to be more expensive than those with higher firmness ratings.
  • What is your weight? People who weigh less than 130 pounds usually feel more comfortable on ‘Soft’ or ‘Medium’ mattresses, while those who weigh more than 230 pounds often prefer higher firmness ratings.
  • What is your preferred sleep position? Generally speaking, side-sleepers are more comfortable on mattresses with lower firmness ratings, while back- and stomach-sleepers prefer mattresses with higher firmness ratings.
  • Do you have chronic back pain or constant pressure/discomfort? If the answer is yes, then you may feel most comfortable on mattresses with mid-level firmness ratings.
  • Is off-gassing a major issue? People who are sensitive to strong smells may prefer firmer mattresses, since they produce less off-gassing odor compared to mattresses with lower firmness ratings.
  • Do you sleep hot? Mattresses with ‘Medium’ or ‘Firm’ ratings typically retain less body heat than those with ‘Soft’ ratings, and sleep cooler as a result.
  • Do you plan to use the mattress for sex? Mattresses with lower firmness ratings tend to be more responsive — and thus, better for sex — than those with higher firmness ratings.
  • Do you plan to move/rotate the mattress on your own? Mattresses with lower firmness ratings tend to be heavier (due to additional padding layers) than firmer mattresses. Additionally, less firm mattresses need to be rotated more often on average.
  • What type of pillows do you own? Low-loft pillows are best paired with mattresses that are less firm, while high-loft mattresses go with firmer mattresses. If you do not own pillows with the right loft level, then you may need to purchase new ones in order to feel comfortable.
  • Are firmness exchanges allowed? Before committing to a specific brand, be sure to review the terms of their sleep trial and mattress warranties. In some cases, you will not be able to exchange your mattress for a model with a different firmness once the initial purchase has been made.

To compare different mattress brands and models based on firmness and other factors related to comfort and support, please visit our Mattress Review Database.