How to Choose Mattress Firmness: Soft, Medium or Firm? (Australia Guide)
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What Mattress Firmness Should You Choose?
Most Australians should choose a medium-firm mattress (6–7/10), as it provides the best balance of spinal support and pressure relief.
Soft mattresses suit side sleepers and lighter individuals, while firm mattresses are better for back or stomach sleepers and heavier body types.
This is the simplest and most accurate starting point. But choosing the right mattress firmness isn’t just about picking “soft” or “firm” — it’s about how your body interacts with the mattress over a full night’s sleep.
The right firmness should:
- keep your spine aligned
- relieve pressure on key areas
- feel comfortable in your natural sleeping position
And that’s where personal factors come in — especially your sleeping position, body weight, and comfort preference.
Mattress Firmness Scale
Mattress firmness is typically rated on a 1–10 scale, which helps standardise how soft or firm a mattress feels:
- Soft (1–3): Deep sink, plush feel, high contouring
- Medium (4–6): Balanced comfort and support
- Medium-Firm (6–7): Support-focused with slight cushioning
- Firm (8–10): Minimal sink, strong support and stability
In Australia, the majority of mattresses sold fall within the medium to medium-firm range, as these options tend to suit the widest range of sleepers.
One important thing to keep in mind: firmness is not absolute. The same mattress can feel softer or firmer depending on your body weight and sleeping style.
Soft vs Medium vs Firm
| Firmness | Feel | Best For | Key Benefit | Main Risk |
|---|---|---|---|---|
| Soft | Plush, sink-in | Side sleepers, lightweight users | Pressure relief | Poor back support |
| Medium | Balanced | Combination sleepers, couples | Versatility | May feel “in-between” |
| Medium-Firm | Slightly firm | Most Australians | Spinal alignment | Slightly less plush |
| Firm | Hard, supportive | Back/stomach sleepers, heavier users | Strong support | Pressure points |
Medium-firm is the safest choice for most people.
Soft mattresses tend to feel luxurious at first but may lack support over time, while firm mattresses offer structure but can feel too rigid for certain sleepers. Medium-firm sits in the middle — which is why it dominates the market.
What Firmness Do Australians Prefer?
Medium-firm mattresses are the most popular choice in Australia, and this isn’t just a trend — it’s based on how people actually sleep.
There are a few key reasons behind this preference:
- Better spinal alignment for long-term sleep health
- Suitable for a wide range of body types
- More durable, with less risk of sagging over time
- Performs well in warmer climates, where overly soft foams can feel too enveloping
Australian consumers also tend to prioritise support over initial softness, especially when dealing with back or posture-related issues.
That said, “most popular” doesn’t mean “best for everyone.” The right choice still depends on your individual needs.
Best Mattress Firmness by Sleeping Position
| Sleeping Position | Recommended Firmness | Why It Works |
|---|---|---|
| Side Sleeper | Soft–Medium | Reduces pressure on shoulders & hips |
| Back Sleeper | Medium–Firm | Supports natural spinal alignment |
| Stomach Sleeper | Firm | Prevents hips from sinking |
| Combination Sleeper | Medium | Balances comfort and support |
How to Choose the Right Firmness
1. Sleeping Position (Primary Factor)
Your sleeping position is the single most important factor when choosing firmness.
-
Side sleepers → Soft to Medium
This helps reduce pressure on the shoulders and hips -
Back sleepers → Medium to Medium-Firm
Supports the natural curve of the spine -
Stomach sleepers → Firm
Prevents the hips from sinking too deeply
If you tend to move around during the night, a medium or medium-firm mattress is usually the best compromise.
2. Body Weight
Firmness perception changes depending on your weight:
- Under 60kg → Choose softer
- 60–90kg → Medium works best
- Over 90kg → Choose firmer
Heavier bodies compress the mattress more, which makes it feel softer than intended. Lighter individuals, on the other hand, may find firm mattresses too hard.
This is why the same mattress can feel completely different from one person to another.
3. Support vs Pressure Relief
A good mattress isn’t just about comfort — it’s about balance.
- Choose softer if you feel pressure in your shoulders or hips
- Choose firmer if you experience lower back discomfort
The ultimate goal is a neutral spine position, where your back stays aligned without excessive sinking or stiffness.
Why Medium-Firm Is Usually Recommended
Medium-firm mattresses offer the best balance between comfort and support for most sleepers.
They:
- keep the spine properly aligned
- reduce the risk of long-term back pain
- work across multiple sleeping positions
- suit both individuals and couples
Because of this, many Australian mattress brands design their products around this firmness range.
If you’re leaning towards a firmer feel, you can explore some of the top-rated options in this guide to the Best Firm Mattress Australia to see which models offer the right balance of support and comfort.
Common Mistake to Avoid
One of the biggest mistakes people make is choosing a mattress based only on how it feels in-store.
Testing a mattress for 5–10 minutes doesn’t reveal:
- long-term support performance
- pressure buildup over hours
- how your spine aligns during sleep
Because softer mattresses feel more comfortable initially, many people end up choosing something that lacks proper support.
Over time, this can lead to:
- poor sleep quality
- back or joint discomfort
- faster mattress wear
What Happens If You Choose the Wrong Firmness?
| Too Soft | Too Firm |
|---|---|
| Hips sink too deeply | Pressure on shoulders/hips |
| Poor spinal alignment | Lack of contouring |
| Lower back pain | Discomfort during sleep |
| Faster sagging over time | Reduced sleep quality |
The right mattress should feel comfortable and keep your spine aligned — not just one or the other.
Quick Mattress Firmness Guide
If you just want a quick answer, here’s a simple rule of thumb:
- Side sleeper + light weight → Soft–Medium
- Combination sleeper → Medium
- Back sleeper → Medium-Firm
- Heavier body → Medium-Firm–Firm
If you’re unsure, choose medium-firm (6–7/10) — it’s the most reliable starting point.
Final Takeaway
The best mattress firmness isn’t about choosing the softest or the firmest option — it’s about finding the right balance for your body.
A good mattress should:
- support your spine
- relieve pressure points
- adapt to your sleeping position
For most Australians, that balance is found in the medium-firm range, but your final choice should always be based on how you sleep and what your body needs.
FAQ
What firmness mattress is best in Australia?
Medium-firm (around 6–7/10) is best for most Australians because it balances support and comfort, making it suitable for a wide range of sleepers.
Is a firm mattress better for back pain?
Not always. A medium-firm mattress is usually better because it supports the spine while still providing enough cushioning to prevent pressure points.
Should side sleepers choose a soft mattress?
Yes, side sleepers generally benefit from soft to medium mattresses, as they reduce pressure on the shoulders and hips.
How do I know if my mattress is too soft?
If your hips sink too deeply or you wake up with lower back pain, your mattress may not be providing enough support.
