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Finding the right level of firmness is an important part of choosing a mattress. Select a mattress that is too soft or too firm, and you may be uncomfortable and even wake up with back pain. Many mattresses aim to offer an ideal firmness level for all sleepers, but the fact is that your mattress firmness needs will depend on multiple factors, including your weight, body size, and the position in which you sleep.

In this guide, you’ll find out why mattress firmness matters to you and which level of firmness may be best for your needs. You can also consider mattress selection criteria related to firmness including support, conformability. We also have tips for choosing your right mattress firmness and guides to help you find the right mattress for your weight, sleeping position, and more. This guide even highlights some of the online mattress companies that offer soft, medium, and firm mattresses.

Mattress Firmness and Why it Matters

A mattress with the wrong firmness for your needs can cause back pain, discomfort, even unnecessary heat. A mattress needs to be firm enough to offer adequate support, but still soft enough to conform to your body and relieve pressure points. But too firm or too soft is often a matter of opinion and can change depending on your weight and even the position you sleep in.

Mattress Firmness vs. Support

Firmness is an important factor in any mattress choice, but it’s not the only one you should be looking at. And it’s important to understand that firmness is not the same as support and vice versa. While firmness determines how hard or stiff a mattress feels when you first lie down on it, support indicates how well a mattress keeps your spine aligned properly — regardless of how soft or firm the mattress is. You should look for a mattress with good support and the right level of firmness for your needs. It’s also important to consider conformability, or how well a mattress is able to contour to the curves of your body in the position that you sleep.

Firmness Scale

We’ve rated mattress firmness from soft to firm on a scale of 1 to 10, with a 1 almost as soft as a pillow while a 10 is nearly as hard as a rock. Of course, extremes like 1 or 10 are unusual and should be avoided. Nearly all mattresses will fit within our scale without reaching a 1 or a 10.

  • 1 (very soft): The softest available with a plush sleeping surface most people will sink into deeply.
  • 2-3 (soft): Good sinkage, contouring, and softness.
  • 4-6 (medium): Right in the middle of soft and hard, usually with a very good balance of firmness, support, and conformability.
  • 7-9 (firm): Firm without compromising all comfort or conformability.
  • 10 (very firm): Extremely hard with little padding or conformability.

Remember firmness is not the same thing as support. Support refers to how well a mattress keeps your spine aligned. While firm mattresses tend to offer stronger support, a softer mattress may offer support with fewer pressure points.

Note: Mattress firmness is highly subjective. While many people may agree on the firmness level of a particular mattress, not everyone will. A mattress that feels firm for one person may not feel the same way for another. Mattress comfort depends on many factors, including weight and sleeping position. These can greatly influence how soft or firm a mattress feels to a particular person. It’s essential to keep in mind that your particular needs will play an important part in how comfortable and soft or firm a mattress feels to you.

Soft Medium Firm
Support good good great
Conforming excellent good not good
Sleep Positions side side, back, and stomach back
Companies Amerisleep, Saatva, Helix Sleep, Novosbed, Brooklyn Bedding, Luxi, Drommabed Purple, Ghostbed, Hyphen, Lull, Voila, Winkbeds, Endy, Luxi, Drommabed, Helix, Novosbed, Saatva Casper, Leesa, Tuft & Needle, Saatva, Yogabed, Novosbed, Helix, Voila, Drommabed, Luxi

Soft (1-3)

  • Support: Despite common misconceptions, soft mattresses can provide good support, but they can be hard to find. Mattress shoppers should look for a model that has a good balance between softness and support.
  • Conforming: Conforming is where soft mattresses really shine. With softer materials, soft mattresses are easily able to contour and hug curves.
  • Sleep positions for soft mattresses: Side sleepers can do well with a soft mattress. A soft, supportive mattress gives a better contour for sides. Back and stomach sleepers may also appreciate softness.
  • Selected online and direct to consumer soft mattresses: Amerisleep, Saatva, Helix Sleep, Novosbed, Brooklyn Bedding, Luxi, Drommabed

Medium (4-6)

  • Support: Medium firm mattresses usually offer adequate support without feeling too firm.
  • Conforming: Typically, medium firm mattresses are still soft enough to have good conformability, supporting curves without sinking.
  • Sleep positions for medium mattresses: Medium firm mattresses are suitable for all sleep positions, including back, side, stomach, or a combination of all three. They offer support with minimal pressure and good conformability, which works for all sleeping positions.
  • Selected online and direct to consumer medium mattresses: Purple, Ghostbed, Hyphen, Lull, Voila, Winkbeds, Endy, Luxi, Drommabed, Helix, Novosbed, Saatva

Firm (7-10)

  • Support: Firm mattresses usually have very good support.
  • Conforming: Firm mattresses are typically not soft enough to provide excellent conformability.
  • Sleep positions for firm mattresses: Back sleeping is the best position for firm mattresses. While sleeping on your back, pressure is more evenly distributed on the body. Side sleepers and stomach sleepers may struggle on a firm mattress, as they need better conformability and can have difficulty with pressure points.
  • Selected online and direct to consumer firm mattresses: Casper, Leesa, Tuft & Needle, Saatva, Yogabed, Novosbed, Helix, Voila, Drommabed, Luxi

How to Choose Your Ideal Mattress Firmness

Weight Sleeping Position
Soft light, average side
Medium light, average, heavy side, back, and stomach
Firm heavy back

By Weight

  • Light (130 lbs or less): Soft or medium firm mattresses (2-5) are best for light people, as they may be too light to feel any conforming on a firm mattress. Without enough pressure on the mattress, light people may essentially float on a too firm mattress and and suffer from pressure points. Light people will feel more of top layers and less of supporting foam, so comfortable and conforming top layers are important for light people.
  • Average (130-230 lbs): Medium firm mattresses (4-6) are typically ideal for average sized people, though some prefer the feel of a soft mattress. Most medium firm and universal comfort mattresses are designed to offer good firmness and comfort for people of average weight. Average sized people may choose a softer mattress if they prefer better conformability or sinkage.
  • Heavy (230 lbs or more): Heavy people do well with a medium or firm mattress (6-9). They place more pressure on a mattress and as a result, tend to sink too low into soft mattresses. Medium to firm support mattresses will offer both support and comfort. Heavy people should also look for a thick mattress, ideally 10 to 12 inches thick with at least six inches of support to avoid bottoming out.

Sleeping Position

  • Back: Medium to firm mattresses (4-9) are good for back sleepers, as pressure on the body is evenly distributed.
  • Side: Side sleepers do well with medium to soft mattresses (2-6), which allows them to enjoy conforming properties of a softer mattress.
  • Stomach: Medium firmness (4-6) is usually just right for stomach sleepers, who can suffer from pressure points on a firm mattress or fall too deep into a soft mattress.

Sex

  • Soft: Soft mattresses (2-3) are not ideal for sex. They tend to have less bounce and can be tough to move on during sex as partners sink more deeply into them.
  • Medium: Medium mattresses (4-6) are comfortable while being easy to move on, so they are the best for sexual activity.
  • Firm: Firm mattresses (7-9) may not be comfortable for all partners and can also transfer excess movement to the bed frame, potentially causing too much noise.

Tips for Ideal Mattress Firmness

  • Be very careful with soft mattresses: Soft mattresses can be a perfect fit for some sleepers, but when they’re a bad fit, they’re really bad. They can be difficult to move on, sleep hot, and sag more easily.
  • Avoid extreme ends of the soft or firm scale: It’s best to avoid mattresses that fall on the far ends of the scale of soft or firm. These mattresses are likely to be too extreme for the average sleeper.
  • Stick with medium if you’re not sure: One size doesn’t always fit all, but according to our data, the majority rules. Medium firmness mattresses tend to be just right for most sleepers.
  • Be ready for motion transfer if you decide to go with very firm mattresses: Very firm mattresses have little give. That means every movement you make isn’t absorbed by the mattress. Rather, it transfers to your bed frame or partner.
  • Consider your partner’s needs: What works for one sleeping partner may not work for the other. Be sure to pay attention to the level of firmness, support, and conformability your partner may need when you’re shopping for a mattress and find one that is a good compromise for both of you.