firm vs medium mattress
Buying Guides

Firm vs Medium Mattress: Understanding What’s Right For You

    Last Updated
    January 18, 2023
    min read

    You may be asking yourself, should I buy a firm or medium firm mattress? Getting mattress firmness right can mean all the difference when it comes to a good night's sleep. 

    The main difference between a firm and medium mattress is the amount of give the mattress has. A medium mattress allows the body to sink in more. Whereas a firm mattress has less give.

    Although everyone feels a mattress differently. This can be impacted by preferences, body shape, weight, and more. Fortunately, there are key things to know that will help you decide between a firm and medium mattress. We will cover those in this guide.


    What Is Mattress Firmness?

    mattress firmness scale

    Mattress firmness refers to a mattress's comfort when lying down on it. The mattress firmness scale typically goes from 1-to 10, one being the softest and ten firmest. However, as lovely as a soft mattress sounds, it doesn’t always mean that it’s the best for you

    Personal preferences are still vital since they affect your comfort levels and sleeping position. For example, a heavier person might want to consider a firmer mattress, while a petite sleeper would sleep better on softer or medium mattresses.

    The firmness level of a mattress can also depend on the type of mattress. 

    It is also important to note that firmness does not equal support. Here’s an easy way to break down the difference:

    • Support: Spine alignment and how to best make your sleeping position comfortable
    • Firmness: How you immediately feel when you lie down

    How To Measure Medium vs Firm Mattress

    When picking a mattress, it’s not all about the length and width. One thing to consider is the “plush” or “plushness” of a mattress. Think of soft mattresses and how soft they feel when you lie down – that’s what plush is.

    For medium, medium-firm, and firm mattresses, their “plush” leans more on how much “support” it can give rather than how soft it is. A good example is the Purple Mattress, a medium-firm mattress that uses different comfort layers to maintain its plush and support for a wide range of sleepers.

    Another way to understand this is by checking your current mattress. Soft mattresses often cause you to sink when you lie down. Meanwhile, firmer mattresses give a more solid feel – you can actually feel the bed's surface pressing against your back as you lie down.

    Pros Of Firm Mattresses

    Firm mattresses certainly have their benefits, including:

    • Best for heavier body types/heavier sleepers: Firm mattresses have excellent support and plush when keeping the mattress firm, so it’s best for heavier sleepers or those with more bodyweight. This support prevents the mattress from sinking and causing body aches.
    • Spinal alignment: Unlike soft mattresses, firm ones can result in better spinal alignment for a wide range of sleepers and sleep styles. It helps those with back pain, as long as it isn’t too firm of a mattress.
    • Highly recommended for stomach and back sleepers: If you’re comfortable sleeping on your stomach or back, a firm mattress can keep your torso from sinking and relieve your spine or abdomen pressure. 

    Cons Of Firm Mattresses

    • Can be uncomfortable for lighter bodyweight/lighter sleepers: For light sleepers, a firm mattress can provide little to no give.
    • motion isolation: Choosing a firm mattress lets you toss and turn on the bed. However, sometimes, it is not as comfortable for the sides of your body or if you want to stay put on one side of the bed.
    • Not a great option for side sleepers: People with this sleep style are more likely to develop body pain and spinal misalignment if they get a firm mattress. So, it isn’t a wise decision to get it if you have this kind of sleep style, especially if you’re the type to shift to your other side in your sleep.

    Pros Of Medium Firm Mattresses

    Not to be confused with medium mattresses, a medium-firm mattress is a type of mattress that sits in between firm and medium. These beds aren’t too soft but aren’t too firm, either. With it comes certain benefits that you can find in both:

    • Suitable for light sleepers to average sleepers: A medium-firm mattress is perfect for light and average-weight sleepers. It has a soft padding that is comfortable for these body types as well as firm padding that offers proper weight body support.
    • Allows for motion isolation: If you’re the type to switch between two or more positions in your sleep, a medium-firm mattress is perfect. It creates enough firmness for you to move around, but it also allows for motion isolation that stops you from moving so much that it causes body aches in the morning.
    • Fantastic for side sleepers and combination sleepers: For side sleepers and combination sleepers, a medium-firm mattress allows them to manipulate the bed to the contour of their body. 

    Cons Of Medium Firm Mattresses

    • Not the best option for heavier body types: Heavier body types might find it difficult to sleep on medium-firm mattresses since they typically need more resistance to keep a neutral spine alignment. This is why softer mattresses like medium-firm mattresses are recommended for lighter sleepers.
    • Stomach sleepers: All the weight from your body goes to the front, which can cause back pain. Sleeping on a medium-firm mattress or any softer mattresses in this position can further this problem.

    What Is The Difference Between Firm vs Medium Mattress Firmness?

    The difference between firm vs. medium mattress firmness is that a medium mattress is more on the plush side while a firm mattress is on the support side. A medium mattress is not to be confused with a medium-firm mattress, which is the middle point between a firm mattress and a medium mattress. 

    It is best to check how both mattresses feel when lying down on them to know the difference. But if that’s not possible or you’re buying the mattress online, looking at the mattress material is another good way to gauge its plushness. Memory foam mattresses are more likely used for medium and soft mattresses, while hybrid mattresses are commonly found on firm mattresses.

    For example, Purple’s memory foam and hybrid mattresses are made of two different materials that can go from soft to firm. 

    What Makes A Comfortable Mattress?

    Finding the best mattress firmness for you is important since you’ll be spending at least 8 hours on it every day. Sleeping on too-soft mattresses can cause long-lasting back and stomach pain, while overly firm mattresses can be too hard on your sides.

    There are many factors to consider when finding the right firmness level. Below are a few essential considerations:

    Sleeping Position

    Sleep positions can determine what mattress firmness you should get. For example, firm mattresses may not be suitable for side sleepers since it causes spine misalignment over time. A better option for that would be soft mattresses or medium mattresses. 

    Here are some recommendations based on sleep positions:

    • Stomach sleepers: Sleeping on your stomach is the unhealthiest sleep style and can cause back problems. Firm mattresses are the best for these sleepers as they help maintain neutral alignment.
    • Side sleepers: To sleep comfortably on your side, you need to cushion your shoulders and hips. A good option for this is medium mattresses, as their level of firmness is enough to provide pressure relief around those areas.
    • Back sleepers: Sleeping on your back can cause more discomfort than pressure relief. For this, it’s best to get medium and medium-firm mattresses since they provide comfort and support to your back.
    • Combination sleepers: Combination sleeping is the most common sleep style there is. Sleepers like this change their sleeping positions a lot in their sleep – a firmer mattress like a medium-firm mattress is the best option for a good balance of support and comfort.

    Body Type

    For every body type, there is a bed that provides the best comfort and support. Here’s the perfect mattress for your body type:

    • Lighter sleepers: For lighter body types, it’s recommended to get a high plush mattress or a softer mattress. 
    • Light sleepers: Those with light bodyweight can opt for a soft mattress up to a medium.
    • Average sleepers: People of average bodyweight have a wide range of mattress selections. We recommend a medium to a medium-firm.
    • Heavy sleepers: For heavier body types, it is recommended that they get firm mattresses. However, if they want a little plush, they can add memory foam mattress toppers.

    Mattress Type

    A comfortable mattress is often determined by its mattress type. For example, memory foam mattresses are made out of materials that soften when heat is applied to them. This creates pressure relief for sleepers and provides warmth on those cold winter nights.

    Spinal Alignment

    The majority of Americans reported recent episodes of back pain, with most of it being chronic and resulting in limited everyday activities. However, according to some studies, good sleep can alleviate physical pain like headaches and chronic body pain. 

    The best way to get good sleep is a good mattress. Here’s a quick rundown on how firm and medium mattresses help with spinal alignment:

    • Firm: Firm mattresses help support spinal alignment, especially for heavy sleepers and those who sleep on their stomach and back. However, it’s not recommended for people who rest on their sides or are lighter sleepers since it doesn’t contour the shape of their body and can cause more spinal damage.
    • Medium-firm: Medium-firm mattresses are the best for most body types and sleep styles. It is also the most cost-efficient option if you prefer to spend more on pillows for body support and comfort.
    • Medium: If you want to have more cushion on your spine when you sleep, medium mattresses are your best bet. If you feel that it has too much plush, buying a mattress made out of GelFlex Grid like Purple’s collection can address that.

    Number Of Sleepers

    The number of sleepers on a firm and medium mattress are things you need to consider, even if you buy the largest bed size. A good rule of thumb is that if you’re sharing a bed with someone, opt for a medium to medium-firm mattress. This way, you can play it safe and cater to all types of sleepers.

    Frequently Asked Questions On Firm vs Medium Mattress

    Are there mattresses with adjustable firmness levels?

    Yes! Many mattress companies have a wide range of mattresses with an adjustable firmness scale. The key here is the comfort layers. Mattress companies like Purple have beds ranging from latex mattresses to plush mattresses.

    Are firm mattresses better for you?

    As aforementioned, there are a lot of factors to consider if a firm mattress is good for you. However, firm mattresses are better if you have back problems and want to align your spin.

    How can you make a mattress softer?

    Although the mattress firmness level is adjustable to a certain extent, making it softer is a little trickier. A good option is to get a mattress topper. Adding a mattress topper made out of memory foam can make your current mattress feel softer.


    When choosing between a firm vs a medium mattress, things such as sleeping position, body type, mattress type, etc. need to be accounted for. Generally, firm mattresses are good for your back, while medium and medium mattresses are good for your comfort. 

    If you’re still not sure what your dream bed would feel like, you can always add mattress toppers or benefit from Purple’s 100-night trial and money-back guarantee


    About the authors

    April Seifert

    April has nearly a decade of writing experience, with 3+ years specializing in sleep content. Her work has been covered by sites like BuzzFeed, Entrepreneur, and Money Under 30. She has an M.A. in Magazine, Newspaper, and Online Journalism from Syracuse University and a B.A. in Communication Studies. As a self-proclaimed expert in all things cozy, she sleeps better at night, knowing her writing helps others sleep in comfort, too.