How to Make a Mattress Firmer [15 Hacks for 2025]

Have you been waking up with back pain and not feeling well-rested? There could be several reasons for this, but one might be that your mattress isn’t as firm as it used to be. Over time, as you use your mattress, it may become softer overtime. Your doctor may have advised you to sleep on a firmer surface if you have a back injury or are experiencing back discomfort. 

If this is the case and you aren’t ready to upgrade to a new mattress, here are a few things you can do to make your mattress firmer. 

1. Adjust The Temperature

If you have a memory foam mattress that is losing its firmness, check the thermostat and the room temperature. Memory foam mattresses are temperature sensitive, absorbing heat and becoming soft in warmer rooms/climate and firmer in cooler temperatures. Your mattress may get firmer if you lower the temperature in your room. 

2. Put Your Mattress On The Floor

Another way to firm up your mattress is to place it on the floor. Many people might not want to give up their bed frame so this might be a last resort option for many. Remember that putting your mattress on the floor makes it more vulnerable to germs and pests. If you suffer from back pain, sleeping with your mattress on the floor might help. 

3. Replace The Plywood

If your mattress is a bed with plywood slats, replacing them might be the solution to firming up your mattress. A piece of plywood cut to fit your bed frame can also be placed underneath the mattress. Before adding the new plywood, make sure it is not treated and is sanded to prevent splinters. 

4. Flip It

Not every mattress is designed for flipping. If yours is, flipping your mattress might firm it up. Before flipping your mattress, double check that it is designed for flipping and utilizing both sides. Flipping your mattress helps to even out the wear and strain on your mattress and keeps it firm. Depending on how worn out your bed is, it is best to flip your mattress every 6 months.

5. Get A Mattress Topper

One of the quickest ways to firm up your mattress is to get a mattress topper. Most mattress toppers are made from either soft or firm memory foam (you can find latex toppers as well). 

Available in a variety of firmness levels and sizes, it should be easy to find a mattress topper that will make your mattress firmer. Make sure to purchase a topper and not mattress pad. Pads are thinner and are not designed to create a firmer surface.

6. Replace Worn Out Layers

Some mattresses are made with multiple layers that are joined together and can be replaced. If you have a layered mattress, you can easily replace any worn or damaged layers rather than buy a new mattress. Before opening up your mattress, make sure you can purchase replacement layers. Contact the manufacturer for assistance. 

7. Get A New Box Spring 

Over time, wear and tear on the coils of your mattress's box spring can loosen. It's possible that you need a new box spring if your mattress has lost firmness. A new box spring will help make your bed firmer and add some height.

8. Smooth Out Your Bedding

Rumpled up and ill-fitting sheets are uncomfortable. Putting the correct sized sheets on your bed can also help firm it up. Use a sheet that is the same size as your mattress and pull tight from top to bottom and side to side. This will produce pressure on the mattress and make it feel firmer.

9. Add Some Additional Plywood

Many bed frames have plywood slats included. Adding a piece of plywood to your bed frame and mattress can make your mattress firmer. Try placing a piece of plywood between the box spring or bed frame and the mattress. This adds an additional layer of support beneath your mattress, preventing it from sinking.

10. Take Advantage Of The Trial Period

If you recently purchased a mattress and it’s not as firm as you hoped, the quality is lacking, or the mattress isn’t the right fit for you, take advantage of the trial period and return or exchange the mattress. 

This will only work if your mattress is still under warranty or in the trial period. Certain warranties might not cover this so double check your warranty or call the manufacturer for more information. 

11. Dry Your Mattress In The Sun

If you live in a humid area, your mattress is going to absorb moisture from the air. Excessive moisture can lead to mold and mildew that can damage your mattress and decrease firmness. If you think this might be the problem with your mattress, take your bed and place it in the sun to dry out. 

This will not only firm up the mattress, but it will also eliminate any bacteria or germs that may be present. If this does not work, it is best to throw out the mattress. Mold and mildew can lead to infections, allergies, asthma, damage to surfaces, and rotting.

12. Buy A New Mattress

If all else fails, it might be time to buy a new mattress. The support and firmness of your mattress is critical for spinal health and preventing body pain and stiffness–a worn out mattress in general is bad for your health. In the long run, it will be more beneficial to your health and wallet to make the initial investment in a new mattress instead of spending more on firming techniques that might not help.

What Is the Right Firmness Level For You?

Firmness is relative; what is firm for one person may not be firm enough for another. When shopping for a mattress, select the firmness that is the best fit for you and what you (and your partner, if you have one) find the most comfortable. If you need some guidance when trying to decide on a firmness level, the best way to determine is by your body weight and build.

Body Weight

Each body type and size benefits from different firmness levels. Along with your body weight, take into consideration any back pain issues you may have as a firm or medium/firm mattress will be the best fit for you. 

Here’s an overview of the best firmness levels for petite, average, and plus-size sleepers.

Petite Sleeper

Petite sleepers, or those under 130 pounds, typically find a soft or medium-soft mattress will give them the firmness and support they want. They will still feel “on top” of the mattress without a sinking feeling.

Average Weight Sleepers

Average weight sleepers are those between 130 and 230 pounds. Individuals in this group tend to go with a medium or medium-firm mattress. This firmness level provides adequate support while letting the sleeper experience the plushness of the mattress surface.

Plus Size Sleepers

Those who weigh more than 230 pounds are considered plus-size and a firm bed is usually the most comfortable option. Plus-size sleepers will feel lifted and supported on a firm mattress. The more weight on the mattress the more it will compress, so a firm mattress will provide the most comfort and support.

Sleeping Positions

When choosing a mattress, it's easy to overlook your sleeping position. Besides body weight, this is one of the most important factors to consider when choosing a mattress. Different firmness levels will work the best for different sleep positions. Here’s a rundown of sleep positions and the mattress firmness that works the best for them.

Back Sleepers

A mattress that is medium-firm to firm is usually the most comfortable for back sleepers. Choose a mattress that will support your back while also cradling your neck. Back sleeping keeps the spine neutral and helps prevent pain.

Stomach Sleepers

Sleeping on your stomach can cause a lot of back pain. Once you’re used to sleeping on your stomach, it can be hard to break the habit. The weight of your midsection will put strain on your spine, causing it to curve if your mattress is too soft. If you sleep on your stomach, it’s best to get a medium-firm mattress.

Side Sleepers

Side sleepers are the most comfortable on a soft to the medium-soft mattress. The best mattress for side sleepers should conform to the body, alleviating pressure on the hips and shoulders while also straightening the spine.

FAQ

Still, have some questions about making a mattress firmer? Here are a few more considerations and things you might be wondering about.

Is a mattress pad the same as a topper?

No, a mattress pad is different from a mattress topper. The main purpose of a mattress pad is to make the bed softer. If you're looking for a mattress topper to firm up your bed, make sure you don't accidentally buy a mattress pad.

Do I have to get a firm mattress?

Firmness is subjective, so you might not need a firm mattress. But firm mattresses are recommended for plus-size sleepers, people who suffer from back pain, and those healing from a back injury.

What is the quickest way to make my mattress firmer? 

A mattress topper is the quickest and easiest way to make your mattress firmer. Remember that a mattress topper will not fix sagging but will only make the mattress top firmer. There are many mattress toppers available so it won’t be difficult to find one that suits you.

Are there any considerations for memory foam? 

Memory foam is sensitive to temperature and exposure to warm temperatures for a long period of time can cause your mattress to lose firmness. Keep your memory foam mattress cool to keep it in the best shape. 

Is a soft mattress bad for my back? 

A mattress that is too soft can cause back pain. If you’ve noticed your back hurting when you wake up, it might be time for a firmer mattress.

What if my mattress is sagging? Can I fix it and make it firm again?

Possibly. You can try some of these tips to see if it helps. If your mattress is sagging too much and these tips don’t help, it’s best to get a new mattress. 

Do I have to make my mattress firmer? 

The short answer is no, you don’t have to make your mattress firmer. However, it is better for your spine and overall health to sleep on a supportive mattress. 

 

These techniques can help make your mattress firmer when it begins to sag or lose its support. This is completely normal and will happen with wear and tear. Making a mattress firmer can be a challenge and might not work for every mattress and/or person. Once you’ve tried these methods and did not get the desired results, it might be time for a new mattress. 

If you think a new mattress is the best option for you, SleePare can help! Our website features thousands of mattress recommendations, guides, comparisons, and more to help you find your perfect mattress. Visit our website to learn more. 

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