Mattress Firmness Guide

Learn what mattress firmness really means and how to determine which firmness is best for you

By Alesandra Woolley

Apr 14th, 2022

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Mattress firmness is one of the most subjective factors when it comes to choosing a mattress – it really depends on your own personal preference. While there are criteria to help you choose which firmness level might be the most comfortable for you, it’s important to remember that everyone is different.

Choosing your mattress firmness can be an overwhelming process (especially if you’re not sure what it really means), but we’ll break down the basics for you – in plain old English – and help you choose a level of firmness that will be best for your sleeping needs.

What does mattress firmness really mean?

Mattress firmness is just how soft or hard a mattress feels. (Really…that’s it.) The firmness of your mattress is directly related to how comfortable you feel on that mattress. And since everyone’s different, there’s no exact science for what level of firmness you’re going to be most comfortable with.

However, factoring in things like your body type, weight, age and sleeping position can help you determine the general range of firmness that other sleepers like you tend to prefer. We’ll get to that later, but if you’re on the edge of your seat, then have a look here.

A mattress can be softer or firmer depending on the materials used and how the mattress is constructed. If you’ve been doing some mattress research lately, you’ve probably seen that some mattress brands offer different levels of firmness (soft, medium, firm), or sell one universal model and indicate the firmness level on a scale from 1-10 (with 10 being the firmest).

Brands that only offer one “type” of mattress typically fall in the medium firm range of the spectrum (6-7 out of 10). You’ll even see some brands, like Helix, that will customize the firmness level to your liking based on how you answer their short questionnaire.

The important thing to know when talking firmness is that firmness does not mean the same thing as support. So, a softer mattress doesn’t necessarily mean it won’t offer you sufficient support, and vice versa. Support refers to how well a mattress holds and distributes your body weight (science + gravity), while firmness refers to how soft or hard the mattress feels (comfort + personal preference). Sure, the two are related, but not interchangeable.

Read our guides on the best firm mattresses and best soft mattresses for mattress brands that provide good support at both ends of the firmness spectrum.

What is the mattress firmness scale?

The mattress firmness scale was developed as a universal way to measure how soft or firm a mattress is on a scale from 1 to 10, with 1 being the softest and 10 being the firmest. (This isn’t the only scale out there to measure firmness, but it’s one of the more popular ones.)

No matter how extreme you like to consider yourself, you’ll want to stay away from mattresses on either end of the spectrum (1, 2, and 9, 10). Most mattresses fall within the 5-7 range, which is what a majority of sleepers tend to prefer.

Before you read any further, you should know that the firmness scale is not the end-all, be-all when it comes to selecting your mattress. For example, an innerspring mattress that’s a 6 on the firmness scale can still feel completely different than a memory foam mattress that’s also a 6. Now take that same 6 memory foam mattress – you and your spouse may also feel completely different sleeping on that same mattress.

Use this firmness scale purely as a guide. The only sure way to tell if you’re going to be comfortable in a mattress is to sleep on it for a period of time (at least a few weeks).

Here’s a general breakdown of the different levels on the firmness scale and what they mean:

  • Soft: Usually a 3-4 out of 10
  • Medium: Usually a 4-6 out of 10
    • Will still hug and contour your body, but not as much as soft
    • Your body will feel slightly more raised on the mattress
    • Tends to be better for side or combination sleepers
    • Examples of medium mattresses: NolahNectarLayla (soft side)
  • Medium-firm: Usually a 6-7 out of 10
    • Most popular level of firmness
    • Will have more resistance and response than soft/medium mattresses
    • Tends to better for stomach or back sleepers
    • Examples of medium-firm mattresses: LeesaCasperPurple
  • Firm: Usually a 7-8 out of 10
    • Will feel like you are sleeping “on” the mattress as opposed to “in” it
    • Very minimal hug or contour; harder surface
    • Tends to better for stomach or back sleepers
    • Examples of firm mattresses: Leesa HybridLoom & Leaf (firm), airweave

You’ll also find mattresses with half number firmness scores (like 6.5) or ranges (6-6.5). If a mattress brand does not have their firmness score readily available on their website, just ask. Most mattress companies are pretty responsive over live chat. You can also take a look at our mattress buying guide where we’ve listed the firmness of a number of different mattresses for you and our top mattresses of the year for some great bed recommendations.

How do I know which mattress firmness is best for me?

The honest answer to this question is: you won’t know until you try it. But that answer isn’t very helpful, now is it? There are a few different factors that can help you decide how comfortable you may feel in different levels of firmness depending on your body type and sleep positions. But remember, this is a very subjective topic.

WEIGHT  

Your body weight is directly related to gravity, and therefore the amount of pressure that’s applied to the mattress when laying on it. So the more weight you carry, the more you’ll tend to sink into the mattress. And (you guessed it) the less weight you carry, the less pressure you’ll put on the mattress. So theoretically, that would mean lighter people tend to prefer softer mattresses, while heavier people tend to prefer firmer mattresses.

It’s worth noting though that the firmness scale was developed to account for the weight of an average-sized adult (170-190 pounds), so if you’re particularly light (under 120 pounds) or on the heavier side (250+ pounds) you might want to opt for something a little softer (for the lighter folks) or a little firmer (for the heavier folks) than you may think you’ll need.

GENDER / BUILD

We’re certainly not going to say anything here like females prefer softer mattresses and males prefer firmer mattresses because that would just be silly. However, your build and body type will have an effect on the comfort level you’ll experience on any particular mattress. And as you know, men and women tend to differ in their build and body type. If you’re planning on sharing your mattress with someone who has a different body type than you, make sure you’re factoring that into your buying decision. Most couples tend to prefer a medium to medium-firm firmness level mattress so both sleepers can feel comfortable on the mattress.

SLEEPING POSITION

Based on the position you usually sleep in, you may prefer a different level of firmness. This has to do with how much pressure is placed on certain parts of your body while you’re resting in that position.

  • Side sleepers: Side sleepers tend to prefer mattresses built for side sleepers that fall on the softer side because they cradle heavier parts of the body, like the shoulders and hips, that need more pressure relief in this position.
  • Back sleepers: Many back sleepers tend to prefer medium-firm to firm mattresses (many of our recommendations on our best mattress for back sleepers list), however, back sleepers can find comfort in a range of different firmness levels. The most important thing for back sleepers is finding a mattress that will keep the spine in its natural alignment. And as we mentioned above, this also has to do with your weight and build.
  • Stomach sleepers: Because firmer mattresses will push up on your body more, stomach sleepers tend to find the most comfort in mattresses that fall on the firmer end of the spectrum. Firmer mattresses will help elevate the pelvis and hips, which is important for relieving pressure in these areas when sleeping on your stomach. If this is you, head over to our best mattress for stomach sleepers page.

Related: Best mattress for combination sleepers

AGE

Age is just a number. But we’re just going to leave this here: firmer mattresses will inherently be easier to get out of. So if you’re older and getting out of bed isn’t as easy as it used to be (or if you’re not old and still find this hard), then a firmer mattress might be the way to go.

PERSONAL PREFERENCE 

Personal preference is truly the most important factor when choosing the firmness of your mattress. Here’s a way to think of firmness that might help you decide where your preferences fall: if you like sleeping “in” the mattress (sinking in a little, feeling hugged), then you’ll probably prefer a softer mattress; but if you prefer to sleep “on” your mattress (feeling more like you’re floating), then you might find more comfort in a firmer mattress.

Related: Best pillow top mattresses

If you’re considering a mattress from a company that offers multiple levels of firmness and you’re not sure which one is going to be best for you, just shoot a note to customer support. Most mattress companies have a live chat feature so you can receive your answer pretty quickly. They may ask you for things like your body type, height, weight, personal preference and which position you typically sleep in.

And if you still can’t decide, our recommendation is to opt for a firmer mattress. It’s easier to make a firm mattress feel softer than to make a soft mattress feel firmer.

Which brings us to our next topic…

What if I don’t like the firmness of my mattress?

If you’re not satisfied with the firmness of your mattress, you can:

  • Add a mattress topper (to make a firmer bed feel softer)
  • Change your pillow (to better compliment the firmness of your mattress)
  • Return it and get a different mattress
  • Check out our tips to make a mattress firmer

Adding a mattress topper, especially a down or plush topper, can make a firm mattress feel softer. Since this is the layer that will be closest to your body, it can be a cheaper and easier alternative than changing your mattress altogether.

Changing your pillow can actually have a significant impact on how comfortable you feel on your mattress. If you’ve recently switched the firmness of your mattress or are planning to, you’ll want to make sure your pillows also compliment that new firmness. For firmer mattresses, you’ll generally want a pillow that is a bit thicker to provide proper support for your head and neck. For softer mattresses, a thinner, plusher pillow might be more comfortable for you since your body will be sinking into the mattress more and you’ll want your head/neck elevation to match.

Returning your mattress might seem like a hassle, but most mattress companies today (especially online-only brands) offer generous trial periods and risk-free return policies that make this process a breeze. If you’re hesitant about trying out a new firmness, make sure you review the trial period and return policy before making your purchase.

If you’re still not sure about the firmness of your mattress, here are some ways you can tell if it’s too soft or too firm for you:

How to tell if a mattress is too firm: How to tell if a mattress is too soft:
  • Pressure points don’t feel supported and your shoulders or hips feel like they are above the rest of your body
  • You’re waking up feeling sore or achy
  • You’re waking up or feeling disturbed every time your partner moves (firmer mattresses usually don’t absorb motion as well)
  • It’s difficult to get out of bed (you feel like you’re stuck or too sunk in the mattress)
  • Pressure points are dipping down – your shoulders and hips sink below the rest of the body
  • You’re waking up feeling achy or in pain

Still have questions about mattress firmness? Drop us a line in the comments below and we’ll do our best to get you the information you need.