How To Make a Mattress Firmer [13 Tips + Tricks]

Some of the simplest ways to make a mattress firmer include adding a firm mattress topper, or using a solid mattress base. You may also consider checking your warranty and possibly replacing your mattress with a firmer option.

If you’re wondering how to make a mattress firmer, you’re not alone. 

Maybe you woke up with a sore back or noticed that you’re just not sleeping as well as you used to. Your mattress that used to feel just right is suddenly going soft. Whatever the reason, we’ve got plenty of techniques to get back to your preferred mattress firmness, so you can start feeling well-rested again. 

Read on to learn more about how to make a mattress firmer and why mattress firmness matters. 

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It’s worth mentioning that while firmness and support are similar, they’re actually two separate factors in a mattress. Support issues like sagging relate more to mattress quality than anything else, while firmness speaks to a comfort preference. 

1. Check Your Trial Period and Warranty

If you’ve recently purchased your mattress and find it's too soft, you may be able to return it for a refund or exchange it for a firmer model. Many mattress retailers provide a generous window for returns or exchanges to ensure the buyer has enough time to decide if the mattress is the right fit. 

Purple offers customers a full 100-night trial that lets them get to know their mattresses and ensure it’s a good match. However, if your mattress is truly causing discomfort, poor sleep, or pain, it’s worth contacting the retailer even if it’s outside the trial or warranty period. Even if they aren’t able to accept a return or exchange your mattress, they may have additional suggestions for how to make a mattress firmer. 

2. Purchase a Mattress Topper 

Mattress toppers are an additional layer of foam or gel added on top of a mattress. Usually, they’re used to make a mattress softer, but there are firm options as well. Mattress toppers can also help make your bed warmer or cooler, depending on the material. 

Note that a firm mattress topper won’t work on every mattress, as it may reduce the mattress's benefits — which is the case with Purple’s GelFlex® Grid. 

Some different mattress topper options include:

• Latex toppers: Latex toppers are a great option if you’re looking for something to make your mattress firmer, while also improving durability, temperature regulation, and bounce.
• Memory foam toppers: Memory foam is generally quite soft and conforms to a sleeper's body. However, there are firmer options available. 
• Polyfoam toppers: Polyfoam is generally the most affordable mattress topper option. This high-density foam is very supportive and durable. 

3. Keep Your Sheets Tight

Keeping your sheets and other bed coverings tight provides pressure on the mattress to create a drum effect. This can help to both extend and increase firmness. 

To make your bed properly and tightly:

• Ensure you use the right size sheets for your bed, including any additional layers you may have, such as a mattress topper. 
• Clear everything off the bed while making it. 
• Consider using the hospital corners method of making the bed, which makes for a tight fit.

4. Air It Out

High humidity where you sleep can cause your mattress to retain moisture and soften over time. If your bedroom is humid or if you live somewhere coastal, this may be the cause of your mattress softening. 

Try airing your mattress out by removing all of the bedding and opening the windows to let fresh air in. Leave it like this for as long as possible. You may also consider getting a dehumidifier for your bedroom to help remove moisture from the air. 

5. Lower Your Room’s Temperature

Some mattresses will stay firmer in cool temperatures and soften in warmer ones. In particular, memory foam mattresses are especially sensitive to temperature. 

Try sleeping in cooler temperatures by turning on a fan or turning down your thermostat. This should help keep your mattress firmer for longer. 

6. If Possible, Replace Worn-Out Layers

In some instances, you may be able to replace some of the layers within your mattress rather than replacing the entire thing. This will be entirely up to the manufacturer of your mattress. 

Some will offer replacement top comfort layers as they start to wear down, so you may be able to replace the too-soft layer with something firmer. Contact your manufacturer directly to see if this is an option. 

7. Use a Bunkie Board

A bunkie board is essentially a 1-to-3-inch thick piece of plywood or particle board that goes beneath a mattress. It provides a solid foundation for soft mattresses, such as foam or hybrid, and can help prevent mattress sagging. A bunkie board will therefore provide additional support, but may not actually make a mattress firmer.

Bunkie boards are a more affordable alternative to a box spring and provide a good barrier between bed frame slats and the mattress without adding too much height. Because a bunkie board can help fix a sagging mattress, it can also make the mattress firmer. However, a bunkie board will not make all mattresses firmer, including Purple mattresses. 

8. Buy a New Mattress Base

The base of the mattress is the structure a mattress sits on. The terms "mattress base," "foundation," and "bed frame" are often used interchangeably, but they aren’t the same. A mattress base can be used on its own to support the mattress, whereas a frame will require a mattress foundation of some sort, such as a box spring or slats. 

Changing the type of base you use can provide better support but may not help make your mattress feel firmer. For example, a different base will not impact the firmness of a Purple mattress because of the high-quality materials that compose it. Mattresses with a soft top layer will not feel firmer, even with an improved mattress base. 

If you’re looking for a new bed frame, Purple has several great options.

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9. Upgrade Your Slats

Slats are the wooden or metal planks that go under a mattress and within the base of a bed frame. For innerspring mattresses, bed slats can be a great way to provide additional support because they provide a sturdy foundation. 

However, slats may not be a good option for increasing firmness for many foam or hybrid mattresses, such as Purple mattresses. This is because the slats may cause the mattress to sag over time, as the mattress begins to form into the gaps in the slats. Upgraded slats can improve the level of mattress support by decreasing the amount of sagging. 

10. Repair or Replace the Box Spring or Foundation

While box springs and foundations are quite similar, they do have some differences. A mattress box spring is made of steel springs and generally has some bounce to it, whereas a foundation is a solid sleeping surface, usually featuring wooden slats and no springs. Box springs can wear over time and may need to be replaced more often than foundations. 

To make your mattress more supportive, you may consider switching to a foundation, which provides more even support. Keep in mind, however, that not all beds are designed to go with box springs, including Purple mattresses. 

11. Regularly Rotate Your Mattress

One of the simplest ways to keep your mattress supportive and allow it to wear evenly is by regularly rotating the mattress. Most manufacturers recommend you rotate your mattress at least once a year. Rotating your mattress will help with support, but won’t necessarily improve firmness. 

To rotate a mattress, simply turn it 180 degrees, switching where your head and feet rest. Rotating the mattress is different than flipping it, where you switch the side you sleep on from the top to the bottom — in other words, the sideresting on the base. Most modern mattresses have a soft top layer, regardless of what they are made of, and are therefore not designed to be flipped in this way.  

12. Place Your Mattress on the Floor

Aesthetically speaking, foregoing  a bed frame may not be the ideal choice, but some people swear by placing their mattress directly on the floor to firm it up. This method of making a mattress firmer provides a very sturdy base for the mattress, which decreases the risk of sagging and can provide even support. 

This option is similar to using a bed bunkie by providing an even layer of equal support under the mattress. Putting the mattress on the floor is a more economical solution, as it doesn’t require an additional purchase. 

However, a mattress on the floor is not breathable, which is not ideal for people who get hot at night. And because of this lack of airflow, there’s a higher risk of moisture getting into the bed, which may even lead to mold in the mattress. 

Purple mattresses should not be placed directly on the floor for these reasons, as it will likely impact the quality and longevity of your mattress. Additionally, it’s important to note that while placing a mattress on the floor may improve support, it won’t improve firmness. 

13. Invest in a New, Firmer Mattress

If your mattress still feels too soft after trying a variety of firming methods, it may be time to replace your mattress. Here are some signs it’s time to invest in a new mattress:

• Your mattress has started to sag, no matter which base you use or how tight you pull your sheets.
• You’re waking up stiff and sore. 
• You’re not sleeping as well as you used to.
• You’ve noticed your mattress smells mildewy or moldy.

As a general rule, mattresses should be replaced about every seven years, depending on the type of mattress. Latex mattresses can be good for as long as 15 years, while a waterbed might need to be replaced as early as two years. 

If you’re looking to dispose of your old mattress and try a new one, consider Purple. With Purple’s revolutionary GelFlex® Grid, you’ll get the comfort you want and the support you need for a better night’s sleep. Find a range of soft and firm options within the Restore Hybrid Collection. 

Mattress Firmness: Why It Matters

Deciding on mattress firmness largely depends on personal preference, but that’s not the only factor. While soft mattresses may feel great initially, a too-soft mattress can not only impact your quality of sleep but can also cause aches and pains. 

But a too-firm mattress can be just as problematic. Long story short, you don’t want a mattress that is too soft or too firm — you want one that’s just the right amount of each! 

The Unmistakable Benefits of a Firm Mattress

There are several benefits of a firm mattress, including:

• Neutral spine alignment: Firm mattresses are great for back pain as they provide a solid surface that allows for neutral spine alignment. 
• Positive hip positioning: A firm mattress is ideal for back and stomach sleepers, as it ensures your hips do not sink out of alignment.  
• Better weight support: Firm mattresses are ideal for heavier users, as they have better and more even weight support. 

Which Mattress Firmness Is Right for You?

If you’ve experimented with several methods of how to make a mattress firmer but still find that you’re experiencing disrupted sleep or aches and pains, it may be time to get a new, firmer mattress. 

Purple has a range of mattresses to fit every sleeper. From firm options for back sleepers and heavy individuals to soft mattresses for side sleepers, Purple’s mattresses are made for everybody and every body. 

Not sure which mattress is the right fit for you? Take our mattress quiz to find out.