Some mornings, it feels like your mattress gave up before you even did. You shift around, chasing the sweet spot, but all you hit are soft patches and zero support.
If your bed feels more like a sponge than a sleep surface, it might be time to do something about it.
Key Takeaways
- You can make a mattress firmer with practical solutions like adding a firm mattress topper, reinforcing your bed base, or rotating the mattress.
- A firmer mattress offers better spinal support, reduced aches and improved durability, especially helpful for back and stomach sleepers.
- Understanding mattress firmness helps you choose the right feel for your body, whether you prefer soft cushioning or stable, even support.
We’ll walk you through how to make a mattress firmer, why firmness matters, who firmer mattresses are best suited for, and how to pick the right feel for your body.
Whether you’re dealing with a memory foam dip, a too-soft topper, or just want more support under your back, this guide’s for you.
Jump to a section:
- How to Make a Soft Mattress Firmer
- Benefits of a Firm Mattress
- Who Is A Firm Mattress Best For?
- How to Choose the Right Mattress Firmness
- Stuck With A Mattress That Feels Too Soft?
- FAQs
How to Make a Soft Mattress Firmer
OK, so your mattress is feeling more sunken than supportive. Maybe it started out plush in a good way, but now it’s just… too much give.
You’ve got options. From small tweaks to more permanent fixes, these eight methods can help bring back that firmer feel and better support.
1. Add a Firm Mattress Topper
A firm mattress topper is one of the quickest and most effective ways to make a soft mattress feel more supportive. It adds a dense, stabilising layer that helps reduce sinkage and gives your body a flatter, sturdier surface to rest on.
Most toppers are between 5 and 10 cm thick and sit neatly under your fitted sheet. Choose one that’s dense and supportive enough to hold its shape through the night.
The material makes a difference too, so here’s a quick breakdown:
Latex
Latex toppers feel springy and don’t sink much, making them great for firmer support without trapping heat. Natural latex is more durable and eco-friendly, while synthetic versions are more budget-friendly.
Memory Foam
You’ve probably heard memory foam described as soft and contouring, but it comes in firmer styles too. Look for high-density foam if you want proper support.
At Ecosa, we’ve designed a firm mattress topper using memory foam that adds structure without locking in warmth.
Polyfoam
If you’re after a quick fix on a budget, polyfoam is worth a look. It’s lightweight and firmer than you might expect, but it usually won’t last as long as latex or memory foam.
2. Give Your Mattress a Better Base
Replace weak slats or a sagging foundation to instantly improve how firm your mattress feels. A soft or uneven base can throw off support and cause unwanted sinkage.
If you’re using a slatted bed frame, check for cracks or bowing. Slats should be no more than 7.5 cm apart.
And, if you’re upgrading, consider a bed base with solid slats made from lightweight, shock-resistant wood for better long-term support.
3. Slide Some Plywood Underneath
Placing a sheet of plywood between your mattress and the bed frame can add instant firmness. It evens out soft spots and gives your mattress a sturdier base to rest on.
Cut the plywood to match your bed frame and keep it flush to avoid shifting. If you sleep on foam, make sure to lift and air the mattress out regularly to prevent trapped heat or moisture.
4. Flip or Rotate Your Mattress
Shifting your sleeping position by flipping or rotating your mattress can help restore firmness in worn-down areas. It spreads out the pressure and gives softer spots a break.
Flip your mattress only if it’s double-sided. If it’s not, rotate it 180 degrees every few months. It’s a small habit that can extend your mattress life and keep it feeling more supportive.
5. Turn Down the Room Temperature
Lowering your bedroom temperature can help firm up a mattress made with memory foam. These materials soften with heat, so a cooler room means a sturdier feel.
Try adjusting the thermostat, using a fan, or cracking a window at night. If you’re sleeping on memory foam and looking for something that stays firmer and cooler, our cooling memory foam mattress is designed to regulate temperature better through the night.
6. Let Your Mattress Breathe
Speaking of cooler sleep, airing out your mattress can help it stay firmer for longer. Trapped heat and moisture can break down the materials inside, especially in foam models.
Strip the bed now and then and leave the mattress uncovered for a few hours. And while you’re at it, avoid going to bed with wet hair or anything damp that could soak into the surface. Small changes like these help your mattress stay fresh and supportive.
7. Return or Replace the Mattress
If your mattress is still under a trial or warranty period, you might be able to swap it for a firmer one. Many brands offer returns or exchanges if the mattress just isn’t the right fit.
If it’s older or showing deep sagging, it could be time for a replacement. Most beds wear out over time.
Not sure if yours is due for a refresh? We cover the signs in our guide on how long a mattress lasts.
8. Short-Term Tricks That Can Help
If you’re after a quick fix, these small adjustments can help your mattress feel a bit firmer without making any major changes:
✅ Tighten your fitted sheet. A tightly stretched bed sheet can reduce surface sag and create a flatter feel. If yours is loose or worn out, consider switching to one that holds better. Our fitted bed sheets are designed to stay in place and last through nightly movement.
✅ Layer towels or blankets underneath. Fold and place them under softer areas of the mattress to boost support.
✅ Use a yoga mat. Slide one between the mattress and base to firm up targeted spots.
✅ Ditch the bed frame (for now). Placing your mattress directly on a clean, dry floor can offer solid support in the short term.
These aren’t long-term solutions, but they’re handy when you’re travelling, hosting guests, or waiting for a better fix.
Benefits of a Firm Mattress
OK, so what do you actually get out of a firmer mattress? Aside from that extra bit of support, it can make a real difference in how your body feels when you wake up.
Here’s how it helps:
Supports Your Spine and Reduces Aches
A firm mattress keeps your spine in a neutral position while you sleep. That alignment helps prevent twisting and slumping, which can lead to pain over time.
It also suits a wide range of sleepers, and even athletes benefit from the extra support, as it helps muscles and joints recover more fully overnight.
Better for Back and Stomach Sleepers
Back sleepers often feel more supported on a firmer mattress. It keeps the hips, chest and shoulders lifted rather than sinking too far into the surface.
That extra lift helps your spine stay aligned and reduces pressure on the lower back. If you’re a stomach sleeper especially, a firmer feel can stop your hips from dipping and throwing your posture out of whack.
Holds Up Better for Heavier Bodies
Softer mattresses tend to wear down faster under more weight. Firmer options offer better durability and consistent support over time.
For people with heavier builds, a firm mattress helps prevent sagging and keeps the spine aligned. That means fewer aches and less tossing and turning through the night.
Who Is a Firm Mattress Best For?
A firm mattress isn’t for everyone, but it could be the right fit if any of these sound familiar:
- You’ve tried a soft mattress and woken up sore. Firmer support may suit your body better, especially if soft surfaces leave you stiff in the morning.
- You run hot at night, or deal with night sweats. Firmer mattresses don’t hug the body as much, which can help reduce trapped heat and improve airflow while you sleep.
- You sit for long hours during the day. If your posture takes a hit from desk work or slouching, a firmer sleep surface can help realign your spine overnight.
- You sleep near the edge of the bed. Firmer mattresses usually have better edge support, giving you more usable space and reducing that slipping or sliding feeling at the sides.
It all comes down to how your body feels supported. If softness isn’t working, a firmer mattress might be just the change you need.
How to Choose the Right Mattress Firmness
Mattress firmness comes down to what feels right for your body. The best fit should keep you supported and comfortable from lights out to wake up.
Here’s a quick breakdown of our mattress firmness guide to help you compare:
| Firmness | Feels Like | Best For |
| Soft | Plush, cushioned, and easy to sink into | Lighter bodies, side sleepers |
| Medium | Balanced feel with light contouring | Most sleepers, combo sleepers |
| Firm | Flat and steady with very little give | Heavier bodies, back sleepers |
Not everyone falls into one category. If you want something that’s not too soft or too stiff, a medium-firm mattress feel might be a better fit.
Stuck With A Mattress That Feels Too Soft?
You don’t have to replace the whole thing just yet. Our firm mattress topper is an easy fix that adds extra support and comfort without the cost of a brand-new bed.
But if it’s time to start fresh, we’ve got you covered there too. Our range of firm mattresses is designed to keep your body aligned and supported night after night.
Whether you’re upgrading or adding a little extra lift, we’ll help you get the sleep you’ve been missing.
FAQs
Can a firm mattress improve back support?
Yes. Firmer mattresses help keep your spine in a more neutral position while you sleep. If your current bed is too soft and you’re waking up sore or stiff, switching to a firmer feel can often help ease discomfort.
How can I make a memory foam mattress firmer?
Memory foam tends to get hot, so cooler room temps can firm it up slightly. For more noticeable results, try a firm mattress topper or placing the mattress on a more supportive base like the floor or plywood.
How do I make a sagging mattress firmer again?
If your mattress is sagging, add plywood between it and the bed base, rotate it regularly, or use layered blankets or towels for targeted lift. These short-term fixes can help delay a replacement while improving support.