Best Mattress Thickness in Australia: How Thick Should Your Mattress Be?

Choosing a mattress can quickly turn into a numbers game.

You’ll see 6-inch, 8-inch, 10-inch, 12-inch and even 14-inch mattresses, all claiming to offer the right balance of comfort and support. But does a thicker mattress actually mean a better mattress?

Not necessarily.

For most adults in Australia, a mattress around 20–30 cm (8–12 inches) can provide a practical balance of comfort, support and overall bed height. However, the ideal mattress thickness depends on more than the number of inches. Your sleeping position, body weight, preferred firmness, mattress construction and whether you sleep alone or with a partner all matter.

So, what is the best mattress thickness in Australia?

For many sleepers, 10–12 inches (25–30 cm) is a useful starting point. Thinner mattresses can work well in certain situations, while thicker mattresses may offer additional comfort layers or support for particular sleepers.

This guide explains what mattress thickness actually means, compares common mattress profiles from 6 to 14 inches, and shows how to choose the right thickness for your body and sleep setup.

Quick Answer: What Is the Best Mattress Thickness in Australia?

If you want the short answer:

• 6-inch mattress: Very thin; generally better suited to specific uses rather than everyday adult sleeping.
• 8-inch mattress: A practical thinner option for lighter sleepers, guest rooms and some simpler mattress constructions.
• 10-inch mattress: A versatile choice for many adults and a common profile for everyday sleeping.
• 12-inch mattress: Provides more room for comfort and support layers and can suit couples, side sleepers and people wanting a more substantial feel.
• 14-inch mattress: An extra-thick option, usually offering multiple comfort and support layers, but not automatically better.

For most Australian adults, 10–12 inches is a sensible range to consider first.

But thickness should never be the only factor.

A well-constructed 10-inch mattress can provide better support than a poorly designed 14-inch mattress.

What Does Mattress Thickness Actually Mean?

Mattress thickness, sometimes called mattress profile or mattress height, refers to the total vertical height of the mattress from its bottom edge to its highest point.

It is different from mattress size.

For example, a Queen mattress in Australia measures approximately:

153 cm wide × 203 cm long

The thickness could then be:

• 20 cm
• 25 cm
• 30 cm
• 35 cm

The Queen size determines the mattress's width and length, while thickness describes how tall it is.

This distinction is important because mattress size and mattress thickness solve different problems.

A Queen mattress gives you more sleeping surface than a Double. A thicker mattress doesn't make the mattress wider or longer—it changes the vertical profile and can allow manufacturers to use different combinations of comfort and support layers.

Is a Thicker Mattress Better?

No. A thicker mattress isn't automatically a better mattress.

This is one of the biggest misconceptions when shopping for a new mattress.

Thickness can be useful because a taller mattress may have more space for different layers. For example, a mattress may combine:

• A breathable comfort layer
• Pressure-relieving foam
• Transition layers
• A supportive core
• Reinforced edge support

But the total thickness doesn't tell you exactly how those layers are constructed.

A 14-inch mattress could contain a large amount of soft material and feel plush, while a 10-inch mattress could use a more supportive construction and feel firmer.

So when comparing mattresses, don't ask only:

"How thick is it?"

Also ask:

"What's inside it?"

This is why mattress thickness, firmness and support should be considered separately.

A mattress can be thick without being particularly firm, and a thinner mattress can still provide strong support.

Mattress Thickness vs Firmness: What's the Difference?

These two terms are often confused.

Mattress thickness

Thickness describes how tall the mattress is.

Mattress firmness

Firmness describes how the mattress feels when you lie on it.

For example:

• A 10-inch mattress can feel soft.
• A 10-inch mattress can feel medium-firm.
• A 12-inch mattress can feel firm.
• A 14-inch mattress can feel plush.

There is no rule that says a thicker mattress must be softer or firmer.

The relationship between thickness and firmness depends on the materials and construction used inside the mattress.

If you're comparing mattresses based on comfort, it's therefore better to consider thickness and firmness together, rather than using thickness as a shortcut for feel.

Common Mattress Thicknesses in Australia

Australian mattress brands offer a wide range of mattress profiles, but shoppers commonly encounter mattresses around 6, 8, 10, 12 and 14 inches.

Here's what each profile generally means.

6 Inch Mattress Australia

A 6-inch mattress is around 15 cm thick.

This is considered a relatively thin mattress profile.

A 6-inch mattress may make sense when:

• You need a lower-profile bed
• You're furnishing a guest room
• You're looking for a simpler mattress construction
• The sleeper is relatively light
• The mattress will be used occasionally

However, a 6-inch mattress leaves less vertical space for comfort and support layers.

For everyday adult use, particularly for couples or heavier sleepers, it's worth paying close attention to the internal construction rather than assuming a 6-inch profile will provide enough support.

Is a 6-inch mattress thick enough?

It can be, depending on the sleeper and construction.

But for a primary adult mattress, a thicker profile may provide more flexibility when it comes to pressure relief, support layers and overall comfort.

8 Inch Mattress Australia

An 8-inch mattress is approximately 20 cm thick.

This is still on the thinner side but can work well for certain sleepers and mattress constructions.

An 8-inch mattress may suit:

• Lighter adults
• Guest bedrooms
• Children and teenagers
• Smaller rooms where a lower bed profile is preferred
• People who prefer a simpler, lower-profile setup

For an adult couple, however, factors such as body weight, sleeping position and motion isolation become particularly important.

Is an 8-inch mattress thick enough?

Yes, it can be—but thickness alone doesn't determine whether an 8-inch mattress will provide adequate support.

This is particularly important for side sleepers and heavier sleepers, who may benefit from sufficient comfort and support layers.

If you're specifically comparing 8-inch mattresses, look at the construction underneath the cover rather than judging the mattress by height alone.

10 Inch Mattress Australia

A 10-inch mattress is approximately 25 cm thick.

This is one of the most practical mattress profiles for everyday adult sleeping.

A 10-inch mattress can provide enough vertical space for a combination of comfort and support layers without making the overall bed excessively tall.

It can be suitable for:

• Back sleepers
• Side sleepers
• Combination sleepers
• Couples
• Average-weight adults
• People who prefer a moderate bed height

Why is 10 inches such a useful mattress thickness?

Because it offers a good middle ground.

You get more room for comfort and support construction than with a very thin mattress, while avoiding some of the excessive height associated with very thick mattresses.

For shoppers looking for a practical everyday mattress, 10 inches is often a good starting point.

12 Inch Mattress Australia

A 12-inch mattress is approximately 30 cm thick.

This is a popular choice for shoppers who want a more substantial mattress profile.

A 12-inch mattress can provide additional space for multiple comfort and support layers, which can be particularly useful for:

• Side sleepers
• Couples
• Heavier sleepers
• People who prefer a deeper mattress feel
• Sleepers wanting stronger separation between comfort and support layers

However, once again, 12 inches doesn't automatically mean better.

The quality and arrangement of the layers matter more than the number printed on the product page.

14 Inch Mattress Australia

A 14-inch mattress is approximately 35 cm thick.

This is considered a thicker mattress profile and is often associated with mattresses containing multiple layers of foam, coils or other comfort and support materials.

A 14-inch mattress may appeal to shoppers who:

• Prefer a taller mattress
• Like a deeper, more cushioned feel
• Want multiple comfort layers
• Need additional support for a larger body
• Prefer a higher sleeping surface

But there's an important trade-off.

A thicker mattress can increase the overall height of your bed considerably.

If your bed base is already tall, adding a 14-inch mattress may make getting in and out of bed less convenient.

So before choosing a very thick mattress, consider the total bed height, not just the mattress.

Mattress Thickness Comparison: 6 vs 8 vs 10 vs 12 vs 14 Inches

The easiest way to think about mattress thickness is as a range rather than a strict ranking.

6 inches

Best for lower-profile setups and specific sleeping situations.

8 inches

A thinner everyday option that may suit lighter sleepers or guest rooms.

10 inches

A versatile profile for many adults and everyday sleeping.

12 inches

A substantial profile that allows more room for comfort and support layers.

14 inches

An extra-thick option for shoppers who prefer a taller, more layered mattress.

The key point is:

The thickest mattress isn't necessarily the best mattress.

Your ideal thickness depends on what your body needs and how the mattress is constructed.

What Mattress Thickness Is Best for Different Sleep Positions?

Your sleeping position is one of the most useful starting points when deciding how much mattress thickness you need.

But thickness shouldn't be treated as a rigid rule.

Best Mattress Thickness for Side Sleepers

Side sleepers place more pressure on areas such as the:

• Shoulders
• Hips
• Knees

A mattress needs enough comfort material to allow these areas to sink slightly while still keeping the spine in a neutral position.

For many side sleepers, 10–12 inches can be a useful starting range.

However, don't choose a thicker mattress simply because you sleep on your side.

The mattress firmness and pressure-relieving properties matter just as much.

A 12-inch mattress that is too firm may still create uncomfortable pressure around the shoulder.

A well-designed 10-inch mattress may provide a better balance.

Best Mattress Thickness for Back Sleepers

Back sleepers generally need a combination of:

• Consistent support
• Pressure relief
• Stable spinal alignment
• Moderate surface comfort

A 10–12 inch mattress can work well for many back sleepers, but the right firmness depends on body weight and personal preference.

The important thing is that your hips shouldn't sink excessively while your lower back remains supported.

This is another example of why thickness should not be used as a substitute for firmness.

Best Mattress Thickness for Stomach Sleepers

Stomach sleepers need to be particularly careful about excessive sinking around the hips and abdomen.

A mattress that's too soft may allow the midsection to sink too deeply.

For many stomach sleepers, a 10-inch mattress with appropriate support and firmness can be a practical choice.

A thicker mattress isn't necessarily an advantage if the additional comfort layers make the surface too soft.

Best Mattress Thickness for Combination Sleepers

If you regularly move between your side, back and stomach during the night, you need a mattress that can adapt to multiple sleeping positions.

For combination sleepers, 10–12 inches is a useful starting range.

But again, focus on the whole mattress:

Thickness + firmness + responsiveness + support

A mattress that is too soft can make movement harder, while one that's too firm may create pressure when you sleep on your side.

Does Body Weight Affect the Mattress Thickness You Need?

Yes, but not in the simple way many shoppers assume.

A heavier sleeper doesn't automatically need a 14-inch mattress.

Instead, body weight affects how deeply you compress the mattress and how much support you need from the underlying structure.

Lighter sleepers

Lighter sleepers may not compress the comfort layers as deeply, meaning a thinner mattress can sometimes provide sufficient comfort.

Average-weight sleepers

Many average-weight adults can comfortably use mattresses around the 10–12 inch range, assuming the construction and firmness are appropriate.

Heavier sleepers

Heavier sleepers should pay close attention to:

• Support core construction
• Edge support
• Material density
• Weight capacity
• Mattress firmness
• Overall structural stability

A thicker mattress may provide more room for layered construction, but support quality matters more than thickness alone.

What Mattress Thickness Is Best for Couples?

Couples don't necessarily need the thickest mattress available.

Instead, think about what both sleepers need.

A couple may want:

• Strong edge support
• Good motion isolation
• Consistent support
• Pressure relief
• Appropriate firmness
• Enough sleeping surface

If one partner sleeps on their side while the other sleeps on their back, the mattress needs to accommodate different pressure and support requirements.

This is where mattress construction becomes especially important.

A well-designed 10–12 inch mattress can be more practical for a couple than a 14-inch mattress that doesn't provide the right support or motion isolation.

Does Mattress Thickness Affect Comfort?

It can, but not by itself.

A thicker mattress may have room for:

• Additional comfort layers
• Transition foam
• More substantial support systems
• Pocket springs
• Different material combinations

These layers can affect how the mattress feels.

However, thickness itself doesn't guarantee comfort.

Think about it this way:

Thickness gives manufacturers more room to work with. Construction determines what they do with that space.

That's why two mattresses with the same thickness can feel completely different.

Does Mattress Thickness Affect Support?

Yes, but thickness isn't the same as support.

A mattress's support depends heavily on its internal structure.

For example, support can be influenced by:

• Foam density
• Support core design
• Pocket springs
• Zoned support
• Transition layers
• Edge reinforcement

This means a 10-inch mattress can provide excellent support if its internal structure is well designed.

Likewise, a 14-inch mattress can still feel poorly supported if its construction isn't suited to the sleeper.

When shopping, look beyond the headline thickness.

Does a Thicker Mattress Last Longer?

Not necessarily.

Mattress durability depends on:

• Material quality
• Foam density
• Construction
• Weight placed on the mattress
• Usage frequency
• Rotation and care
• Base support

A thicker mattress isn't automatically more durable.

In fact, choosing a mattress based solely on thickness can lead to a mismatch between your needs and the mattress construction.

Instead, ask:

Is the mattress built to maintain its support and comfort over time?

That's a much more useful question.

Mattress Thickness and Bed Height

One consideration that's often overlooked is the height of the entire bed.

Your final sleeping height depends on more than the mattress.

Think of it as:

Mattress height + bed base height + mattress topper = total bed height

For example, a 30 cm mattress on a tall bed base can create a significantly higher sleeping surface than a 25 cm mattress on a low-profile base.

This matters if:

• You're shorter
• You have mobility considerations
• You prefer a lower bedroom profile
• You use a mattress topper
• Your bedroom furniture is already relatively high

Before buying a thick mattress, measure your existing base.

Mattress Thickness and Your Bed Base

Your mattress and bed base need to work together.

A suitable base should provide adequate support across the mattress surface and follow the mattress manufacturer's requirements.

This is particularly important for foam mattresses.

If the base doesn't provide sufficient support, the mattress may not perform as intended regardless of its thickness.

When comparing mattresses, always check:

• Compatible bed bases
• Slat spacing requirements
• Weight capacity
• Centre support requirements
• Warranty conditions

Thickness alone doesn't determine base compatibility.

Does a Mattress Topper Change the Thickness You Need?

A mattress topper can change the overall height and feel of your bed, but it shouldn't be treated as a replacement for an appropriately constructed mattress.

For example, if you have a 25 cm mattress and add a 5 cm topper, your sleep surface may effectively sit around 30 cm higher.

A topper can be useful when you want to adjust:

• Surface softness
• Pressure relief
• Comfort

But if your mattress lacks adequate structural support, simply adding thickness on top won't necessarily solve the problem.

How to Choose the Right Mattress Thickness

Rather than starting with a number, work through these six questions.

1. What position do you sleep in?

Side sleepers may prioritise pressure relief.

Back sleepers usually need balanced support.

Stomach sleepers often need stronger surface stability.

Combination sleepers need a balance between responsiveness and support.

2. What's your body weight?

Your weight affects how deeply you compress the mattress.

Don't choose a mattress based on thickness alone. Look at the support system and weight capacity as well.

3. How firm do you want the mattress to feel?

Remember:

Thickness and firmness are different.

If you prefer a firm mattress, don't automatically assume you need a thinner mattress.

If you prefer a softer mattress, don't automatically choose the thickest option.

4. Do you sleep with a partner?

Couples should consider:

• Motion isolation
• Edge support
• Individual firmness preferences
• Body weight differences
• Sleeping positions

A thicker mattress may help accommodate more layers, but construction is still the deciding factor.

5. How tall is your bed base?

Measure your existing base before choosing a thick mattress.

You don't want to end up with a bed that's unnecessarily high simply because the mattress sounded more premium at 14 inches.

6. What is inside the mattress?

This is arguably the most important question.

Look at:

• Comfort layers
• Transition layers
• Support core
• Foam type
• Spring system
• Edge support
• Breathability

The internal construction tells you much more about the mattress than thickness alone.

Onebed Mattress Thickness: 10, 11 and 12 Inches

Onebed offers different mattress profiles designed around different constructions and sleep preferences.

The range includes three useful examples of how mattress thickness can vary without there being a single "best" number.

Onebed Essential — 10 Inches

The Onebed Essential has a 10-inch profile.

For shoppers looking for a practical everyday mattress, 10 inches sits in a useful middle range.

It's particularly relevant if you want:

• A moderate mattress height
• A practical bedroom setup
• A balanced approach to comfort and support
• A mattress that isn't excessively tall

The Essential demonstrates that a mattress doesn't need to be 12 or 14 inches to provide a complete sleeping surface.

Onebed Original — 11 Inches

The Onebed Original has an 11-inch profile, sitting between the common 10-inch and 12-inch categories.

This can be useful for shoppers who want a slightly more substantial profile without moving all the way into a very thick mattress.

The Original is also a good example of why mattress shopping shouldn't be reduced to thickness alone.

When comparing 10-inch and 11-inch mattresses, the difference in height is relatively small. What matters more is how each mattress's construction matches your preferred feel and support requirements.

Onebed Max — 12 Inches

The Onebed Max has a 12-inch profile.

At 12 inches, it sits within the range many shoppers consider when looking for a more substantial mattress.

The Max's profile provides space for its hybrid construction and is suited to shoppers who prefer a responsive mattress feel with a more substantial overall profile.

This makes it a useful option for people specifically considering a 12 inch mattress Australia search, but the decision should still be based on construction, firmness and sleeping preferences—not thickness alone.

10 Inch vs 12 Inch Mattress: Which Should You Choose?

This is one of the most useful comparisons when shopping for a mattress.

A 10-inch mattress may be preferable if you:

• Want a moderate bed height
• Prefer a simpler profile
• Have a lower bed base
• Want a practical everyday setup

A 12-inch mattress may make more sense if you:

• Prefer a taller mattress
• Want more room for layered construction
• Prefer a more substantial feel
• Want a hybrid construction
• Need additional comfort or support layers

Neither is automatically better.

The right choice depends on the mattress construction and your personal requirements.

12 Inch vs 14 Inch Mattress: Is Thicker Really Better?

Moving from 12 to 14 inches may sound like a significant upgrade, but it isn't necessarily one.

A 14-inch mattress may provide:

• Additional comfort layers
• A taller sleep surface
• A deeper plush feel
• More space for complex constructions

But it may also:

• Increase overall bed height
• Make fitted sheets more difficult to match
• Add weight
• Be harder to move
• Cost more

If the extra two inches don't provide a meaningful improvement for your sleeping needs, there may be little reason to choose the thicker option.

What Mattress Thickness Is Best for a Queen Bed?

A Queen mattress doesn't need to be a particular thickness.

In Australia, Queen refers primarily to the mattress's width and length, while thickness varies between models.

A Queen mattress can therefore be:

• 8 inches
• 10 inches
• 11 inches
• 12 inches
• 14 inches

The right thickness depends on the construction and sleeper.

If you're choosing a Queen mattress for two adults, consider:

• Body weight
• Sleeping position
• Motion isolation
• Edge support
• Firmness
• Bedroom height

Can a 10-Inch Mattress Be Good for Couples?

Absolutely.

A couple doesn't automatically need a 12 or 14-inch mattress.

A 10-inch mattress can work very well for two adults if it provides:

• Adequate support
• Good motion isolation
• Suitable firmness
• Strong edge support
• Enough surface comfort

The quality of the construction matters more than simply adding two or four inches of height.

This is particularly important for couples with different sleeping positions.

What Mattress Thickness Is Best for Hot Sleepers?

If you sleep hot, don't choose a mattress based on thickness alone.

Temperature regulation depends more heavily on:

• Breathable materials
• Airflow through the construction
• Foam characteristics
• Cover materials
• Coil systems in hybrid mattresses
• Bedroom temperature

A very thick all-foam mattress may feel warmer than a thinner mattress with a more breathable construction.

If temperature is a major concern, consider cooling mattress construction alongside mattress thickness.

What Mattress Thickness Is Best for Older Adults?

For older adults, the most practical mattress thickness may depend less on comfort layers and more on the total height of the bed.

A very low mattress can make getting out of bed harder for some people.

However, an extremely tall mattress can create its own challenges.

The ideal setup should make it easy to:

• Sit on the edge
• Stand up
• Get into bed
• Move around safely

So when choosing a mattress thickness, consider the mattress and base as one complete system.

Common Mattress Thickness Buying Mistakes

Avoid these mistakes when shopping for a mattress in Australia.

Mistake 1: Assuming thicker means better

It doesn't.

Thickness is only one specification.

Mistake 2: Choosing based on inches alone

Two 12-inch mattresses can feel completely different.

Mistake 3: Ignoring firmness

Thickness does not tell you how firm a mattress feels.

Mistake 4: Forgetting the bed base

A thick mattress on a tall base may make your bed unnecessarily high.

Mistake 5: Ignoring body weight

Support requirements change depending on how much pressure your body places on the mattress.

Mistake 6: Choosing the thickest mattress available

More material isn't automatically more comfort.

Mistake 7: Forgetting your mattress topper

A topper can add several centimetres to the final sleep surface.

So, How Thick Should Your Mattress Be?

If you're still unsure, use this as a starting point:

Choose around 8 inches if:

You prefer a lower-profile mattress or need a simpler setup.

Choose around 10 inches if:

You want a versatile everyday mattress for most adult sleeping situations.

Choose around 11 inches if:

You want a middle ground between 10 and 12 inches.

Choose around 12 inches if:

You prefer a more substantial mattress profile or need room for a more layered construction.

Consider 14 inches if:

You specifically want a very thick mattress and have considered the additional bed height and weight.

But remember:

There is no universal ideal mattress thickness.

The best mattress thickness depends on your body, your sleeping position and the mattress itself.

Final Verdict: 

For most Australian adults, 10–12 inches (25–30 cm) is a practical starting range when choosing a mattress.

A 6-inch mattress can work for specific low-profile or occasional-use situations. An 8-inch mattress may suit lighter sleepers and simpler setups. A 10-inch mattress offers a versatile everyday profile, while 11–12 inch mattresses provide more room for layered constructions. A 14-inch mattress can suit shoppers who specifically want a very thick, substantial mattress.

But the most important takeaway is this:

The best mattress thickness isn't necessarily the thickest one.

Thickness should be considered alongside firmness, support, body weight, sleeping position, mattress construction and bed-base height.

If you're comparing Onebed mattresses, the 10-inch Essential, 11-inch Original and 12-inch Max provide three different mattress profiles, giving you a useful way to compare how mattress height relates to construction and your preferred sleep experience.

Ultimately, don't buy a mattress because the number on the specification sheet looks impressive. Choose the thickness that works with your body, your bedroom and the way you actually sleep.

Frequently Asked Questions

What is the best mattress thickness in Australia?

For most adults, 10–12 inches (25–30 cm) is a practical starting range. The ideal thickness depends on body weight, sleeping position, firmness preference and mattress construction.

Is a 10-inch mattress thick enough?

Yes. A 10-inch mattress can provide excellent comfort and support for many adults when it has an appropriate internal construction. Thickness alone does not determine mattress quality.

Is a 12-inch mattress better than a 10-inch mattress?

Not necessarily. A 12-inch mattress may provide more space for comfort and support layers, but a well-designed 10-inch mattress can be equally suitable depending on your needs.

Is a 14-inch mattress too thick?

Not necessarily, but it may be more than you need. Consider your bed-base height, preferred sleeping position, mattress construction and overall bedroom setup before choosing a 14-inch mattress.

Is an 8-inch mattress good for adults?

An 8-inch mattress can work for some adults, particularly lighter sleepers, but it may provide less room for layered comfort and support construction than a thicker mattress.

Does a thicker mattress mean it is softer?

No. Mattress thickness and firmness are different characteristics. A thick mattress can be firm, while a thinner mattress can be soft.

What mattress thickness is best for side sleepers?

Many side sleepers may find 10–12 inches a useful starting range, but firmness and pressure relief are just as important as thickness.

What mattress thickness is best for heavy sleepers?

Heavier sleepers should look beyond thickness and focus on the mattress's support core, material quality, edge support, firmness and weight capacity. A thicker mattress isn't automatically more supportive.

How thick should a mattress be for couples?

Many couples can comfortably use a 10–12 inch mattress. Motion isolation, edge support, firmness and construction are often more important than choosing the thickest available mattress.

What is the difference between mattress thickness and firmness?

Thickness measures the vertical height of a mattress. Firmness describes how hard or soft it feels when you lie on it. The two are related to mattress construction but are not interchangeable.