How to Make a Mattress Firmer

Disclosure: By clicking on the product links in this article, Mattress Nerd may receive a commission fee at no cost to you, the reader. Read full disclosure statement.

Not everyone wants to sink into a cloud-like cocoon filled with fluffy blankets and an equally fluffy mattress. For some, sleeping on a mattress that feels like you’re floating on a cloud is a recipe for restless nights and even more restless days.

While firmer mattresses are a great investment if you’re looking for more nighttime support, not everyone has room in their budget for a brand-new sleeping surface. If you’re stuck with a too-soft mattress and are in need of some extra support, there are a few things you can do to make it firmer.

6 Ways to Make a Mattress Firmer

You don’t necessarily need to go out and buy a new mattress to get the firmness you desire. There are a few things you can do to increase your existing mattress’ support so you can get a good night’s sleep.

Put it on the Floor

Waking up with back pain? Your bed frame might be to blame. If you’ve been snoozing on an old frame that doesn’t offer much support, your mattress could sag—and that can lead to achy mornings.

A quick, no-cost fix would be to try putting the mattress directly on the floor. It may make you feel like a college kid, but it could just be the support your mattress needs to firm up.

Add Some Plywood

A saggy middle is one of the most common complaints people have about their mattresses. If you’re sinking into your mattress and it’s preventing you from getting comfortable, try adding a few plywood boards.

Slip the boards right between your bed frame and your mattress and voila—an instant firmness upgrade!

Replace Your Box Spring

Is your box spring old and decrepit? It might be time for a replacement. Sleeping on the same one for too long will cause it to wear down and lose its structure.

If your box spring is on its last legs, it probably isn’t giving your mattress the support it needs to stay firm. Replacing it with a new one will help extend the life of your mattress and give you the firmness you crave.

Switch Out Some Layers

It’s time to check that mattress policy. If you’ve had your mattress for years, the materials inside could be broken down and causing it to feel softer than it used to.

Take a look at the layers inside your mattress and see if any of them need to be replaced. Some companies make it easy to switch out old, worn-down layers for new ones to give your mattress a little boost.

Give it Some Sun

If you live in a particularly humid climate, there’s a good chance your mattress has been absorbing a lot of moisture. Dampness inevitably leads to softness, so try letting your mattress air out in the sun for a few hours.

This will help remove any moisture that’s been building up—along with mold or germs—and firm up your mattress so you can get a good night’s sleep.

Try a Mattress Topper

There’s no need to spend a fortune on a new mattress when a mattress topper will do the trick. If your mattress is starting to feel softer than you’d like, opt for a firm mattress topper to add some extra support before you replace the whole thing.

Look for a topper made of latex or dense memory foam. These materials will add some much-needed firmness to your mattress without breaking the bank.

Top Firm Mattresses Available Online

If you do decide you need an entirely new mattress, we’ve got you covered. Check out our top picks below for the best firm mattresses that are available online.

Brooklyn Bedding Plank Firm Mattress

The only thing better than a firm mattress? A firm mattress with not one but TWO firm sides! This ultra-supportive mattress from Brooklyn Bedding is flippable, with one side ranking a 1 7.5 on the firmness scale (out of 10) and the other ranking a 9. It also has excellent motion isolation and a quilted foam top layer for some added cushioning.

Saatva Mattress

Easily one of the most popular mattresses on the market, you can choose this hybrid model in three different firmness levels: plush soft, luxury firm, and firm. Most people go for the luxury firm, but if you like to keep things extra firm, the latter option might be best for you. The Saatva mattress also comes with free white glove delivery and removal, so you don’t have to worry about lugging it around yourself.

Brooklyn Bedding’s Titan Plus

Heavyweight sleepers need a little extra support, and this mattress from Brooklyn Bedding has it in spades. This 11-inch thick hybrid mattress is one of the few that’s specifically designed for plus-sized people, but it ranks only a 7 on the firmness scale, making it one of the least firmer options on this list. Still, its responsiveness keeps you sleeping on top of the mattress instead of sinking into it. We call that a win-win.

Frequently asked questions

Can a mattress topper add firmness?

Absolutely—adding a firm (and high-quality) mattress topper is one of the quickest and easiest ways to make your mattress firmer.

How can I make my existing mattress firmer?

You can try putting your mattress on the floor, using plywood boards to create a barrier between your mattress and box spring, or switching out some layers in your mattress if the company you purchased it from offers that option.

Does putting plywood under a mattress make it firmer?

If your box spring is starting to lose its shape, placing plywood between the boxspring and mattress can help redistribute weight more evenly and add some much-needed support.


Sleeping on a soft mattress isn’t for everyone. If you prefer a firmer feel, there are a few things you can do to make your mattress more supportive. Adding plywood to your box spring, switching out some layers in your mattress, or investing in a new firm mattress are all viable options.

No matter what you choose, make sure you do your research to find the firm mattress that’s right for you. Your sleep depends on it.