Mattress Firmness Guide

If you’re in the market for a new mattress, you’ve probably come across firmness ratings. However, it may surprise you to learn that these ratings are more of an educated estimate than an exact measurement—because mattress firmness is highly subjective.

Your body type, weight, and personal comfort preferences all play a major role in how soft or firm a mattress feels, meaning that the same bed can feel completely different to different people.

The good news is that by understanding how mattress firmness is evaluated within the industry, you can make a more informed decision and choose the right firmness level for your specific needs. In this mattress firmness guide, we’ll walk you through everything you need to know to find your perfect fit.

When a mattress company talks about firmness, it’s describing how the bed feels when you lie on it. Some mattresses are soft and plush, allowing you to sink in and feel cradled by the surface. Others are firmer and more supportive, giving you the feeling of lying on top rather than in the bed. These sensations all relate to a mattress’s firmness level.

To help shoppers—especially those buying online without trying a mattress in person—brands use a firmness scale. This scale typically runs from 1 to 10, with 1 being the softest and 10 being the firmest. Most mattresses fall in the medium-firm range, around 6.5, which tends to be the most comfortable and versatile option for a wide variety of sleepers.

Most soft and plush mattresses fall between 3/10 and 6/10 on the firmness scale, typically featuring soft foam layers and cushioned pillow tops for extra comfort.

Soft mattresses are known for their deep sinkage, close body contouring, and excellent pressure relief, offering a cushy, cloud-like feel. For example, the Helix Sunset rates around 5.5/10, providing a balance of softness and gentle support. The Layla Memory Foam Mattress, which is flippable, has a soft side rated at 6/10 and a firm side rated at 8/10, giving sleepers the flexibility to choose their preferred feel.

It’s quite uncommon to find mattresses rated below 3/10 on the firmness scale, as excessive softness often leads to a lack of support, making it difficult to maintain proper spinal alignment.

Who It’s Right For:

• Lightweight sleepers: Individuals with lower body weight often don’t sink deeply into a mattress and may perceive beds as firmer than they actually are. A soft mattress provides the extra cushioning they need for enhanced comfort.
• Side sleepers: Those who sleep on their sides benefit from softer mattresses, which offer better cushioning around the shoulders and hips. This helps maintain proper spinal alignment and prevents pressure buildup.
• People seeking pressure relief: Soft, contouring mattresses gently cradle the body’s curves and distribute weight evenly, helping to reduce pressure points in common problem areas like the lower back, hips, and shoulders.

Medium-firm mattresses are among the most versatile options available, accommodating a wide range of sleepers. They’re also a great compromise for couples with different comfort preferences. Most medium-firm beds fall around 6.5/10 on the firmness scale, though some may lean slightly firmer at 7/10.

This firmness level offers a balanced feel, typically created by layering softer comfort foams over supportive base materials. The result is a mix of pressure relief and support, with slight contouring in areas of higher pressure but enough lift to keep the spine properly aligned.

Because of their versatility, medium-firm mattresses are widely available in both hybrid and all-foam constructions. Examples include the Helix Midnight, Nolah Evolution, and Birch, all of which provide excellent balance and comfort.

Who It’s Right For:

• Average-weight back and side sleepers: Those weighing between 130 and 230 pounds typically experience the ideal combination of spinal support and pressure relief on a medium-firm mattress. It’s also a good choice for combination sleepers who move between these positions.
• Heavier back sleepers (over 230 lbs): Many back sleepers in higher weight ranges still find sufficient support and comfort on medium-firm beds.
• People seeking balance: If you enjoy a “just right” feel—not too soft and not too firm—a medium-firm mattress delivers the perfect blend of comfort and support.

Mattresses rated 7/10 or higher on the firmness scale are considered firm. It’s rare to find a mattress rated as a true 10/10, since even the Plank Firm—the firmest mattress we’ve tested—comes in at 9/10 on its firm side.

Firm mattresses have minimal sinkage, creating a sensation of being lifted and evenly supported across the entire body. This ensures that every area in contact with the mattress receives consistent, stable support.

Popular firm options include the Helix Dawn, the WinkBed (Firmer model), and the Bear Original, all of which provide strong support and excellent durability.

Who It’s Right For:

• Stomach sleepers: To prevent lower back pain, stomach sleepers need a mattress that keeps their hips elevated and spine aligned—a firm bed typically achieves this balance.
• Heavier individuals (over 230 lbs): Because heavier sleepers tend to sink deeper into softer mattresses, a firm mattress provides the right level of support and stability, helping maintain proper posture and preventing sagging over time.

As always, mattress firmness is subjective, meaning there’s no universal “best” firmness that works for everyone. The ideal level depends on your body type, sleeping position, and personal comfort preferences.

For back sleepers, the goal is to find a mattress that’s firm enough to offer support but soft enough to prevent tension in the lumbar region. Medium-firm mattresses are typically the best fit—they provide sufficient support to maintain neutral spinal alignment while offering just enough cushioning to relieve pressure and pain.

Side sleepers generally benefit from softer mattresses, which provide pressure relief around the shoulders, hips, and lower back. This helps evenly distribute body weight and prevents soreness in these sensitive areas.

On the other hand, stomach sleepers need firmer mattresses—ideally those rated 7/10 or higher—to keep the hips elevated and spine properly aligned. Without that lift, the midsection can sink too deeply, causing lower back pain.

If you’re looking for targeted spinal support and comfort, explore options from our best mattresses for back pain selections, which are designed to help you feel both supported and properly aligned.

While the terms “firmness” and “support” are often used interchangeably when describing a mattress, they actually refer to different qualities. Firmness describes how a mattress feels when you lie on it—whether it’s soft, medium, or firm to the touch. Support, on the other hand, refers to how well the mattress keeps your spine properly aligned while you sleep.

In short, firmness is about comfort and feel, while support is about structure and alignment—and the best mattresses strike a balance between the two.

Choosing the right mattress firmness ultimately comes down to understanding your personal needs and preferences. When deciding between a firm or soft mattress, it really boils down to two key factors: your sleeping position and your body weight.

This is the most important factor to consider. Your preferred sleeping position determines which mattress firmness will feel most comfortable and supportive. Back sleepers typically do best with mattresses in the 6/10 to 7/10 range, offering a balance of support and pressure relief. Stomach sleepers should opt for something firmer, around 7/10 or higher, to keep the hips elevated and spine aligned. Meanwhile, side sleepers generally need a softer mattress, ideally between 5/10 and 6.5/10, to cushion pressure points at the shoulders and hips.

Your body weight plays a major role in how soft or firm a mattress feels. Two back sleepers of different weights—one light and one heavy—can have completely different perceptions of the same mattress. A lighter person may find it firmer, while a heavier person might sink in more and feel it as softer.

Taking body weight into account helps you choose a mattress that aligns with your sleeping position and support needs, regardless of how the manufacturer rates its firmness. If you weigh over 230 pounds and need a bed that provides proper support and durability, check out our recommendations for the best mattresses for heavy people.

If you’re still uncertain about which mattress firmness is right for you, choosing a medium-firm mattress is typically a safe and reliable option. Often referred to as “universally comfortable,” medium-firm mattresses tend to suit the widest range of body types and sleeping positions, offering a balanced mix of support and comfort that works well for most sleepers.

What level of firmness should my mattress be?

• The ideal mattress firmness depends on your body type and sleeping position. Back sleepers generally benefit from medium-firm mattresses, as this firmness helps maintain spinal alignment. Stomach sleepers typically need a firmer mattress to keep their hips properly elevated and prevent lower back strain. Side sleepers, on the other hand, do best with a softer mattress that cradles the hips and shoulders to relieve pressure. Keep in mind that heavier sleepers often experience mattresses as softer than rated, while lighter sleepers tend to find them firmer than expected.

What is the most popular mattress firmness?

• The most popular firmness level is around 6.5/10, also known as medium-firm. This firmness provides a balanced combination of support and pressure relief, making it suitable for a wide variety of sleepers, regardless of body type or sleeping position.

How do I know what mattress firmness I like?

• The right firmness should keep you comfortable while maintaining proper spinal alignment. To find your match, consider both your sleep position and body weight. While softer mattresses may sound appealing for their plushness, they’re not ideal for everyone. Avoid choosing based solely on preference—use your sleep style and body type as practical guides to determine which firmness will help you sleep best.