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When you hear the word 'firmness' in a mattress context, you're probably thinking about how hard the mattress is going to be. Good job! You are actually right. Firmness is about the hardness and softness of the mattress as a whole. It plays an important role in cushioning, body contouring, and how you experience comfort during sleep. Most of the time, you'll hear people say, "I like soft mattresses," or "I prefer a harder bed," but these are words that don't really tell you the full story.

Let's be objective and scientific with this process so you can better understand how firmness affects how you pick a mattress. We want you to make an educated choice to find a mattress that you're comfortable with.



  • What’s Mattress Firmness?
  • Which is the Best Firmness for You?
  • The firmness levels of a flippable mattress
  • FAQs

What’s Mattress Firmness?

Mattress firmness refers to the feeling of hardness or softness when you lay on the mattress. It is usually measured on a 10-point scale to describe the firmness level. On a scale of 1, it means that the mattress is soft. On a scale of 10, it means that the mattress is firm or very hard. Most mattress products fall between the region of 3 to 9, either medium-soft or medium-firm.

The Firmness Scale

The methods that many manufacturers use to measure mattress firmness might differ, but commonly in the mattress world, we use a 10-point scale to describe it. You can find the best mattress firmness according to your needs and preferences.

Firmness LevelFeelCharacteristics
1Extra SoftMaximum Conformity, Maximum Sinkage
2-3SoftConsiderable Conformity, Considerable Sinkage.
4-5Medium SoftHigh Conformity, High Sinkage.
6-7Medium FirmModerate Conformity, Moderate Sinkage.
8Slightly FirmSlight Conformity, Slight Sinkage.
9FirmMinimal Conformity, Minimal Sinkage
10Extra FirmNo Conformity, No Sinkage

Which is the Best Firmness for You?

Sleep style

Your sleeping style or sleeping position has different needs when it comes to firmness. Below are a few points to take into consideration when it comes to sleep position and firmness requirements.

  • Back Sleepers: People that tend to sleep on their backs during sleep will need adequate lower back or lumbar support. A firmer mattress can prevent excessive sinkage that could cause strain on your spine and lead to back pain. Back sleepers need adequate resistance/support so soft mattresses such as full memory foam might not be the best option, especially if you are over 230lbs.
  • Side Sleepers: In the case of people that sleep on their side, there is more pressure that is focused on the hips and shoulders. Hence you will need a mattress that has ample support but has a good sinking range for those particular regions. In such an instance, a memory foam mattress might just be a good fit for a side sleeper of average weight. You should look for a mattress that's either medium-soft or, if you are heavier, medium-firm.
  • Stomach Sleepers: Even though it is usually not advisable to sleep in this position, there are people that find this position comfortable and it is fine. Your back and your neck can suffer from discomfort or pressure due to sagging if your belly does not get enough support. Medium-firm and firm help to keep you from sinking into an uncomfortable depth and thus eliminates unnecessary pressure on your back.
  • Combination Sleepers: Also known as 'toss and turn' sleepers. For these sleepers, you'll need a mattress that can accommodate the frequent position change. It will also need motion isolation, so you or your partner don't get woken up by movement. Again, the general firmness recommendation here would be medium soft to medium firm.
Sleep positionRecommended firmness level
Back sleep
Soft, medium-soft, medium-firm, and firm
Side sleep
Soft, medium-soft, and medium-firm
Stomach sleepMedium-firm, and firm
Combo sleepSoft, medium-soft, medium-firm, and firm

The firmness table above is a general recommendation guide just for reference. We recommend that you try the mattress for yourself and see whether it fits how your sleep. If you are still unsure of what firmness to pick Dr. Craig Liebenson's guide on 'How to Choose a Mattress' would recommend going for a medium-firm mattress as a general rule. Many brands will offer a trial period before you settle on choosing the ideal mattress.

Your weight

Body weight or size is an essential factor that influences your feeling about the mattress.

Body weight or size is an essential factor that influences your feeling about the mattress. For example, light-weight people (less than 130 lbs) tend to place less pressure on the bed surface and sink less, that is, they would feel firmer than the average-sized and heavyweight sleepers (more than 230 lbs) when sleeping on the same mattress.

Therefore, medium soft and medium firm mattresses are recommended for petite sleepers. For the average and plus-sized people (130 to 230 lbs), medium-firm and slightly firm mattresses will comfortably fit their needs and preferences.

Reference weightRecommended firmness level
Under 130 lbs
Medium-soft, and medium-firm
130 lbs to 230 lbs
Medium-firm, and firm
Over 230 lbs
Firm, and extra firm

Suffer from pains

Most mattresses will feature a comfort layer at the top, a transition layer in the middle and a support core or base at the bottom. When you sleep, you exert a weighted downward force onto the mattress. Each of these layers reacts to this weight and resists/supports accordingly so that you won't sink uncomfortably or be overly propped upwards in an uncomfortable position.

It is when the downward force is canceled out by the resistance that you experience a state of zero muscle tension. Some call this neutral spine alignment, but if you read Dr. Craig Liebenson's 'How to Choose a Mattress' article, you'll find that the spine was always curved. Neutral spine alignment doesn't exist, but more about whether the mattress is comfortable for the sleeper.

Mattress types

Innerspring: The oldest mattress in history, it is still popular due to its affordability, bounce, breathability and support. The design uses a coil support core and a thin comfort layer made of foam or latex. Therefore, most innerspring mattresses have an overall firmer feel.

Memory foam: Originally used as a cushioning material in helmets, shoes and chair seating for NASA, they typically offer good pressure relief and provide body contouring exceptionally well. Although there are also alternatives, all foam mattresses tend to be softer compared to other models.

Hybrid: Hybrid mattresses combine the support core of innerspring with the plusher comfort layers of memory foam or latex mattresses. These mattresses have a responsive, resilient surface that contours to lessen pressure. Most customers should be able to choose a hybrid in their preferred firmness range since hybrid mattresses are available in a wide range of firmness options.

Latex: Latex mattresses are known for their exceptional durability and hypoallergenic properties. In addition, latex can disperse the body’s weight over a large surface area due to its responsiveness, thus preventing the body from sinking. There is a huge range in firmness across models.

Sleep partners

If you share one bed with your partner, this factor can affect your decision-making. Your partner's body shape, sleeping preference and weight can vary greatly compared to yours. For example, your partner may have trouble sleeping if your bed is too hard for them. For co-sleeping, medium-firm is typically the best option.

Pillow loft

The height or thickness of the pillow, also known as 'pillow loft,' should be complementary to the mattress. Although there are a number of factors to consider for how high a pillow should be, the easiest method would be to try one that fits your sleep position and that you are not feeling muscular tension in your neck. You may need to consider how the pillow interacts with the firmness of your mattress, as you don't want it to be too high because the mattress is too firm or too soft, which causes the pillow to sink more than you need it to.

Generally speaking, low-loft pillows are better suited to softer mattresses, whereas high-loft pillows typically perform best with firmer mattresses. Sleepers who sleep on a softer bed tend to sink further compared to the firmer one. Thus low-loft pillow can keep their neck in the right position.


OK, you may have a general understanding of the mattress firmness, but still, who could tell me which firmness level fits me most? If you still don’t know, we recommend a double-sided flippable mattress with several firmness options, “Don’t know which firmness level should be chosen” can be easily solved. A flippable mattress can be a great solution for various sleeping problems. It allows you to flip the mattress over and use the other side, which can help alleviate pressure and extend the lifespan of the mattress.

Most mattresses on the market only offer one firmness profile or two at most. SweetNight's Prime memory foam mattress provides four firmness options (soft, medium-soft, medium-firm, and firm) simply by flipping or rotating the mattress to a firmness that fits your sleep needs. 

This is made possible by our patented TMContouring Curve. A mathematically calculated 'S'-shaped cut is made into four different mono bloc
ks of quality CertiPUR-US certified memory foam. These cut layers with different properties and densities are stacked together to create one full memory foam mattress. The curvature cuts provide the perfect balance of foam material to create natural zoned support, and the four different firmness profiles are the signature of this mattress.

The Prime mattress also features a checkered cover design made of breathable and soft anti-pilling fabric for increased durable comfort to give you a great night's sleep.

Our 100-day-full-refund and 10-year warranty policy means that we will guarantee the comfort and quality of the mattress so that you rest assured. Contact our customer service team if you need us to help out with any questions you may have about our products and services.



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