Mattress firmness guide: what level is best and why
Key takeaways
I've learned that finding the right mattress firmness level comes down to these key points:
- Sleep position, feel and body weight: Pick the mattress by how you sleep and the feel you like, then choose the springs for your weight.
- Firmness is subjective: There is no industry standard. What feels firm to a 65kg person will feel soft to a 110kg person.
- Sleeping position: This helps choose the mattress. Side sleepers who like it soft usually prefer the Cloud, back sleepers the Aurora, and stomach sleepers who like it really firm the Cooper.
- Separate support from feel: The main springs provide support, latex creates the immediate surface feel, and micro springs add cushioning.
- Adjustability is key: You can't perfectly predict comfort. The best mattress system provides a good starting point and allows you to fine-tune the firmness level at home.
Firmness depends on you, not the label
The mattress industry has made this simple concept unnecessarily confusing. The core concept is simple: the ultimate question of mattress firmness comes down to how hard or soft the mattress feels.
But the label alone is never enough. You'll see marketing hype about "cloud-like softness" and "orthopaedic support," but nobody tells you the truth: the wrong firmness level will ruin even the highest-quality mattress. In contrast, the right firmness can make a budget mattress feel perfect. I believe this is the single most overlooked factor in the entire industry. The term "firmness" is completely subjective.
What a 60kg person feels is "Firm" might feel like a "Medium" to someone much heavier. Heavier sleepers may require firm springs, but the correct threshold depends on whether they choose soft or medium latex.
The term “firmness” is completely subjective. What a 60kg person feels is "Firm" might feel like a "Medium" to someone much heavier.
How to choose your mattress and springs
Pick the mattress by how you sleep and the feel you like. Side sleepers who like it soft usually choose the Cloud. Side sleepers who prefer a balanced feel, and most back sleepers, choose the Aurora. Stomach sleepers who like it really firm choose the Cooper; otherwise, the Aurora with firm springs.
Then choose the springs for your weight. Sharing the bed? Use the heavier person's weight.
| Mattress | Medium springs | Firm springs |
|---|---|---|
| Cloud | Under 80kg | 80kg and over |
| Aurora | Under 100kg | 100kg and over |
| Cooper | Not available | Always |
These are the standard cut-offs. The mattress quiz fine-tunes them for how you sleep and the feel you like.
Soft springs are available by request for children and people under 50kg, but they are too soft for most adults. Contact us for a quote. If you weigh more than 135kg, call us on (02) 8999 3333 so we can check the setup with you.
Firm latex is also available by request, but it is far too firm for most applications and can cause pressure pain. Firm springs with medium latex usually provide a better balance of firm support and cushioning.
What happened to Levels 2–19?
We used to offer 18 firmness levels, from 2–19. We simplified the choice to make it easier to understand. Now you pick the mattress by how you sleep and the feel you like, then choose the springs for your weight.
Each mattress has a flippable spring unit with 2 at-home firmness settings, so you can still make it firmer at home. If you need to go softer or firmer, contact us and we’ll help with the right adjustment or component.
The spring names changed at the same time. The spring unit we used to call very firm is now called firm, the old firm spring is now medium, and the old medium spring is now soft. The old soft spring, later called very soft, has been discontinued.
How do I know if the mattress is too firm or too soft?
If the springs are too soft for your weight, your hips can sink too far and create a hammock shape. If the support or surface is too firm, pressure can build around the shoulders and hips.
Keep the jobs of each component separate. Latex controls the immediate surface feel. The main springs provide support underneath. Micro springs add cushioning and contouring. The flippable spring unit provides a smaller at-home adjustment.
Firm latex is available by request, but it is far too firm for most applications and can cause pressure pain. Firm springs with medium latex usually provide a better balance of firm support and cushioning.
Forget firmness charts. Feel it yourself.
Everybody’s different. That’s why we build adjustability into every mattress. Try it yourself at our Gladesville showroom.
How sleep position changes the choice of mattress
Sleep position and the feel you prefer help choose the mattress. It does not replace the body-weight calculation for the springs.
Side sleepers
Side sleeping creates concentrated pressure around the shoulders and hips. Side sleepers who like it soft prefer the Cloud, with soft latex over 2 micro spring layers, because it gives those areas more room to settle. Those who prefer a more supportive feel choose the Aurora, with the same micro springs under medium latex.
A common mistake is confusing support with a hard surface. Firm springs can sit under soft latex, so a heavier side sleeper can have strong support underneath without creating pressure pain at the shoulder and hip.
Back sleepers
Back sleepers need enough cushioning to follow the lumbar curve without letting the hips sink too far. Most do well on the Aurora, whose medium latex keeps them on top while the micro springs follow the curve of the back. Those who like it very firm can choose the Cooper.
Stomach sleepers
Stomach sleepers who like a really firm mattress usually prefer the Cooper. Its foam layer and firm springs create a flatter surface and reduce the chance of the pelvis sinking too deeply and overarching the lower back. Otherwise, the Aurora with firm springs is the usual starting point.
Debunking myths about firm and soft mattresses
I hear these all the time. Let’s clear up the two biggest myths about mattress firmness.
Myth #1: “A firm mattress is good for your back”
A firm mattress is not automatically better for your back. A 50kg person and a 120kg person compress the same mattress to very different depths. The goal is neutral spinal alignment, not the hardest possible surface.
A more accurate rule is that people with back pain have more to gain from getting the fit right. The latex controls the immediate surface feel, while the main springs need to provide enough support for the person’s body weight.
Myth #2: “Soft mattresses cause sagging”
Springs rarely sag. Foam softens and develops impressions. If the springs are too firm for the sleeper, the comfort material can be crushed between the body and an unyielding spring unit, which speeds up wear.
Get the spring support right and you do not need excessive amounts of foam to make the mattress tolerable.
Firmness and support: why spring tension matters
I have mattresses in the showroom where the only difference is 0.1mm in the pocket-spring wire. They feel completely different. That small change has a major effect on how the mattress distributes body weight.
The latex changes the surface feel. The main springs determine how the body is held. The micro springs add cushioning. Keeping those jobs separate makes the mattress easier to fit and adjust.
Comfort materials: latex vs memory foam vs polyfoam
These materials sit above the springs and affect surface feel, pressure relief, heat and durability.
Polyfoam
- Usually the cheapest option
- Softens and develops impressions sooner than natural latex
Memory foam
- Good at reducing partner disturbance
- Heat-sensitive, so it can feel softer in summer and firmer in winter
- Creates a slow-sinking feel that some people enjoy and others dislike
- Usually retains more heat than latex or springs
Natural latex
- Responsive rather than slow-sinking
- Open-cell and less heat-retentive than memory foam
- More durable than polyurethane foam
- Available in soft or medium as standard; firm by request
Natural latex over pocket springs gives us a durable surface material and adjustable support underneath.
How to test firmness
When you lie on a mattress in the showroom or during the trial, focus on two priorities.
Priority #1: it must feel good while you are lying on it
Lie down in your normal sleeping position and give yourself time to settle. Ask:
- Is there pressure at the shoulder, hip or lower back?
- Do you feel as though your hips are sinking too far?
- Does your spine feel relaxed and naturally aligned?
There is no universal answer. That is why the showroom lets you try every firmness option rather than relying on a label alone.
Priority #2: it must keep feeling good
A mattress can feel comfortable for five minutes and still soften badly after a few years. This is why we use natural latex, pocket springs and replaceable components.
Common firmness mistakes
Mistake #1: choosing from somebody else’s recommendation
Asking a stranger which mattress feels good is like asking them what size jeans you should buy. Their answer describes their body, not yours.
Mistake #2: changing the mattress too quickly
Your body needs time to settle into a different mattress. Unless the setup is obviously painful, give it time before making a major component change.
Mistake #3: confusing firmness with support
A mattress can have a plush surface and still provide strong support. Soft latex over firm springs is one example: the latex cushions the body while the springs hold it up.
Mistake #4: ignoring the bed base
A mattress follows the surface underneath it. Flexible or damaged slats can create a dip that feels like mattress failure. Use a solid, stable base and avoid curved flexible slats. See our bed-base guide for details.
Use the at-home settings before changing components
Each mattress has two settings, set by which way up the main spring unit faces. We deliver it on the soft setting unless you ask otherwise. Most people sleep on their side, and this setting lets the springs shape around the shoulders and hips.
- Soft side up, no white mesh: soft setting, the most contoured
- White-mesh side up: firm setting, with around 15% firmer spring tension
To go firmer, flip the spring unit so the white-mesh side faces up. To go back, flip it so the side without mesh faces up.
If those settings are not enough, contact us. The 7-month trial includes 2 free firmness swaps, with one component per swap.
We find the right firmness through a good starting recommendation, testing and adjustment—not prediction alone.
Final thoughts: Why adjustability matters
The Ausbeds system gives you a clear starting point without locking you into the first setup. You can adjust:
- the latex surface feel
- the medium or firm spring support
- the micro springs or foam under the latex
- the spring-unit orientation
Choose the Cloud, Aurora or Cooper for your sleep position and the feel you like, then match the springs using the confirmed weight thresholds. If the two at-home settings are not enough, the 7-month trial includes 2 free firmness swaps.
The goal is not to make you choose from a long numbered scale. It is to start with the right components and give you a practical way to fine-tune them.
Gary S. experienced that adjustability under our previous numbered system after switching from a waterbed to the Aurora:
“I thought the 6 would suit me, even though Karl had suggested the 5 might be more appropriate. After giving the 6 a two weeks trial, I had to concede that Karl knows more about beds than I do. I changed the bed to a 5 and it is now perfect.”
— Gary S., ProductReview
Ready to find your firmness option?
Visit our Gladesville showroom to try every firmness option, or call us at (02) 8999 3333 to discuss your specific needs.
Frequently asked questions
What is the firmness of a mattress?
At its simplest, mattress firmness is just how hard or soft the mattress feels. The problem is that this is a completely subjective term. What a 60kg person calls a "firm mattress" might feel like a "medium" to someone much heavier. Because there is no industry standard, Ausbeds separates surface feel from support. You pick the mattress by how you sleep and the feel you like, then choose medium or firm springs for your weight.
Which mattress firmness is better?
The honest answer is that the "best mattress" is different for every single person. Asking which mattress is best is like asking a stranger what size jeans you should get. The right mattress firmness for you depends on your body weight, your primary sleeping position, your body shape, and your personal preference.
Is it healthier to sleep on a firm or soft mattress?
Neither is "healthier" on its own. The "healthiest" mattress is one that matches your body and sleeping position. A mattress that is too firm for your body weight will cause your body to yield to the springs, creating pressure points at your shoulders and hips and contorting your spine. A mattress that is too soft will cause you to "hammock", letting your spine fall out of its natural alignment and often leading to back pain. The goal for a healthy sleep is proper spinal alignment, which is achieved by matching the spring support to your body.
Is a firmer mattress better for your back?
A firmer mattress is not automatically better for back pain. The right mattress for a bad back is the one that fits. For example, a 50kg person would likely find that a "very firm" mattress makes their stiffness worse. That said, some specific conditions, like slipped discs, can require an extremely firm mattress to prevent vertebrae from compressing the discs. But for most people, the goal is neutral alignment, whether that comes from a soft, medium firm, or firm mattress.
About the author
Karl owns Ausbeds. Tired of mattresses that failed too soon, he set up a Sydney workshop to make them properly: honest materials, adjustable designs. He also gives straight mattress advice on Reddit, Whirlpool and OzBargain.
