A mattress that is too soft for your body type and sleep style can cause neck and back pain over time, so it helps to know how to make a mattress firmer if yours has lost the support it needs.
It’s normal for even the best mattresses to show signs of softening after years of heavy use, but luckily there are ways to reverse this – with a few caveats we’ll cover below.
While mattress firmness is subjective, a medium firm feel is adequate for most people, regardless of whether you opt for a hybrid, inner-spring, or memory foam mattress. Softer mattresses, while comfortable at first, can cause lower back pain in some people, leaving the spine out of alignment.
Whatever the cause of your bed’s softness, here’s how to make a mattress firmer.
How to make a mattress firmer: quick tips
Our tips should help you firm up your mattress quickly. But if yours is showing signs of severe sagging, there’s a lot you can do (we’ve got extra advice in our article on how to fix a sagging mattress).
In a hurry? So, here are our top tips on how to make a mattress firmer:
- Swap your mattress for a firmer feel if it’s within the trial period
- Flip or flip your mattress and sleep on the firmer side
- Place your mattress on a bed base with more support
- Place your mattress on the floor if the warranty allows it
- Add a firm bed topper for an instant difference
- Reduce your room temperature to firm the foam
- Air your mattress in the sun to reduce moisture that causes softening
- Use a plywood board under the mattress (this has scratches)
1. Replace it if it is within the trial period
Buying a mattress online has great benefits (not to mention cheaper prices, thanks to the abundance of mattress sales), but one of the downsides is figuring out which firmness suits you.
That’s why manufacturers offer in-house trial periods. These range from 100 nights (the average length) to a full year. If you’re still in the trial period, act now and return your over-soft mattress to a firmer model. Most brands offer free returns and exchanges, although some, like Saatva, charge a processing fee.
If your mattress is out of the trial period, check the warranty to see if you are covered for a certain amount of sagging/sagging. Just keep in mind that sagging isn’t the only cause of softer mattresses – some are made that way.
2. Turn or rotate your mattress
Most mattresses should be changed every three months to spread the wear out and prevent deep sagging in a specific spot. However, there are some mattresses that cannot be rotated – usually models that have specific lumbar support areas (also called zoned support). Precious few, like traditional spring mattresses, can be turned over.
If your memory foam or hybrid mattress can be rotated, do this first, as the softness you are currently feeling in your back and hips will be at the bottom of the bed. Our article answering how often you should flip or rotate your mattress has extra tips.
3. Add a firm mattress
In general, bed toppers are used to soften a mattress, but the huge variety now available means you’ll also find toppers designed to make the mattress firmer. This can also help isolate movement from a restless bedmate.
Latex mattresses are your best option for adding firmness, with the material (made from the sap of rubber trees) providing a firmer, more responsive surface. Luxury sleep specialist Saatva makes a great latex topper, priced at $245 on Saatva (opens in new tab) (see our Saatva mattress selling guide for the latest deals).
If you prefer memory foam, look for a hard foam topper. Our best mattress topper guide shows you this year’s top picks for every sleep scenario.
4. Place your mattress on a support base
Another surefire way to make a mattress firmer is to place it on a bed, platform, or base for greater support. This will add firmness underneath, making your mattress feel firmer overall. A new bed frame will also likely cost a lot less than a new mattress.
Firm edge divans are an excellent choice for a firmer bed as they are designed with solid springs and a rigid frame with wooden sides. A slatted base designed to be rigid without sagging is another great option for adding firmness.
Just don’t choose one where the slats are spaced too far apart, otherwise your mattress (especially a foam one) can dip into the slats, making it softer overall.
5. Place the mattress on the floor
While placing your mattress on the floor will instantly make it firmer, there are some downsides to this approach. First, make sure your mattress can be placed directly on the floor for sleeping. Some mattress warranties, for example, will be voided by this approach (so you won’t be covered for damages).
Your mattress will also accumulate a lot more dust and dirt on the floor, and insects (including bacteria) will find it easier to join you in bed. Place a thin rug under the mattress for protection and clean it regularly (see our guide on cleaning a mattress for tips) to keep germs, stains and other grime at bay.
6. Reduce your room temperature
Most of us know that an excessively hot bedroom makes it difficult to fall asleep and stay asleep, but did you know that it can also affect how soft or firm memory foam feels. If your room is too hot, the foams will soften and lose their support.
Hybrid mattresses with springs are usually fine, but cheaper versions can also lose firmness and stability in the foam areas. To make your mattress firmer at night—and sleep better in general—turn off the heat or program your smart thermostat to turn down the heat about an hour before bed.
7. Put the plywood under it – at your own risk
When it comes to making a mattress firmer, you’ll see this trick pop up a lot. And placing a thin slab of wood under the mattress will do the trick, but just like placing the mattress on the floor, there are a few caveats with this approach.
That is, it is not suitable for use with many materials. Memory foam needs to breathe properly or you could risk mold and bacteria growing in the material. In addition to being bad news for your health, it would void your mattress warranty.
If you want to try the plywood mattress trick, we suggest you speak to your mattress manufacturer first to see if it’s allowed and if they can offer a better solution. Sometimes they will surprise you with a free topper to increase firmness.
8. Air your mattress in the sun
Different types of humidity soften a mattress – this is particularly common in damp areas, houses with poor insulation, or if you live near the beach. If you suffer from night sweats, all that sweat and release of body oils can also cause a mattress to lose its firmness over time.
A quick fix is to take your mattress outside when it’s sunny and warm and let it out in the air for a few hours, with the heat and sun naturally pulling the moisture away. This will not only make your mattress firmer, but it will also kill all the bacteria, germs and mold caused by moisture.
How firm should your mattress be?
A common misconception is that ultra-firm mattresses are the best option for good back health and pain reduction. In fact, a medium firm mattress tends to suit the vast majority of sleepers. This is because medium-firm beds keep the spine in neutral alignment, but are not so firm that they are painful to sleep.
Your body weight and sleep style will also play a role in how soft or firm a mattress should be. Lighter sleepers may do well with a softer mattress than heavier sleepers as they won’t sink as deeply into the mattress. If you’re a dedicated side sleeper, you’re really going to want a slightly softer mattress that cradles your shoulders and hips.
Back and combo sleepers will thrive with medium firmness mattresses, but if you’re a stomach or back sleeper, look for a mattress on the firmer end of the scale to keep your head from sinking into the mattress and throwing your spine out of alignment. .
If you’ve decided to go for a new bed, we’ve rounded up some of our favorite medium firm mattresses below. To further enhance your sleep comfort, check out our guide to this year’s best pillows for all budgets.