What Size Memory Foam Mattress Is Best for Your Bedroom?

Choosing the right mattress size comes down to two core factors: how many people sleep in the bed and how much floor space your bedroom can comfortably accommodate. In Australia, memory foam mattresses are available in five standard sizes, and selecting the wrong one can affect both your sleep quality and how your room functions day to day.

Key Takeaways

• Australian mattress sizes differ from US and UK sizes, so always check local dimensions before buying.
• Single and King Single mattresses suit children, teenagers, and solo sleepers with smaller rooms.
• Queen is the most popular size in Australian bedrooms and fits most couples comfortably.
• King mattresses offer the most sleeping space but require a room of at least 4 x 4 metres.
• Room layout, bed frame compatibility, and furniture placement should all guide your final decision.
• Memory foam responds to body heat and weight, so the right size also affects pressure relief and motion isolation.

Why Mattress Size Matters More Than Most People Realise

It is tempting to focus only on foam density or firmness levels when shopping for a new mattress, but size is the foundation of everything else. A mattress that is too small disrupts sleep, especially for couples or restless sleepers. A mattress that is too large can crowd a room, making it difficult to move around and leaving no space for essential bedroom furniture such as wardrobes, dressers, and seating.

Memory foam, in particular, responds to your body shape and sleeping position. A wider surface allows you to shift positions freely without rolling off the edge, which is especially relevant for side sleepers and those who run hot. A longer mattress benefits taller individuals who would otherwise hang off the end.

Beyond comfort, size affects:

• Motion isolation. Wider mattresses in memory foam allow partners to move without disturbing each other.
• Edge support. Larger mattresses often include reinforced perimeter foam, giving you a usable sleeping surface from edge to edge.
• Room flow. A mattress and frame that fit well leave enough clearance around the bed for safe, comfortable movement.

Australian Mattress Sizes Explained

Australian mattress dimensions follow a standardised set of sizes. These differ slightly from US and UK equivalents, so always check local specs when ordering.

These are the standard dimensions used by most Australian retailers and manufacturers. If you are purchasing memory foam mattresses online, always cross-reference the product specs with these figures to avoid a mismatch with your existing bed frame.

Double: The Often-Overlooked Middle Ground

The double mattress is 138 cm wide, making it a reasonable option for a solo sleeper who wants extra room to spread out, but it is a tight fit for two adults sharing regularly. At 188 cm long, it is also shorter than the King Single and Queen, which can be a drawback for anyone over 180 cm tall.

In Australian households, doubles are most commonly found in spare bedrooms or in apartments where the master bedroom is compact. If you are setting up a guest room and expect occasional shared use, a double can work, but most sleep experts in Australia recommend moving up to a Queen if budget and space allow.

Queen: The Most Practical Choice for Most Australians

The Queen mattress at 153 x 203 cm is consistently the best-selling size in Australia, and for good reason. It comfortably fits two adults, suits most standard Australian master bedrooms, and works with the widest range of bed frames and bedding products available locally.

For couples, a Queen provides each person with roughly 76 cm of personal sleeping space, which is comparable to a standard Single mattress on each side. That is enough room for most people to sleep comfortably without crowding the other person, especially in a memory foam model that absorbs movement rather than transferring it.

When a Queen is the right call:

• Your bedroom is between 3 x 3.5 metres and 4 x 4 metres.
• You share the bed with a partner and at least one of you is an active sleeper.
• You want a wide selection of frames, base options, and accessories without paying a premium.
• You are furnishing a rental property or investment space where versatility matters.

A bedroom styled around a Queen also allows space for a chest of drawers without the room feeling cluttered, giving you functional storage without sacrificing comfort.

King: Maximum Space, Specific Requirements

A King mattress at 183 x 203 cm is the largest standard size available in Australia and is the answer to what size memory foam mattress is best for couples who value space above all else. Each person gets approximately 91 cm of width, which is actually more than a Single mattress and close to a King Single.

The trade-off is floor space. A King mattress with its frame typically requires a bedroom of at least 4 x 4 metres to leave adequate clearance on the sides and at the foot of the bed. In a room smaller than this, a King bed can dominate the space entirely, making the room feel like a corridor.

King mattress suits you if:

• Your master bedroom is generously sized, 4 x 4 metres or larger.
• You or your partner is a restless sleeper, or you sleep with children or pets regularly.
• You want maximum surface area for pressure relief across a larger body frame.
• You are making a long-term investment in a premium sleep setup.

How to Measure Your Room Before You Buy

Getting the mattress size right starts with accurate room measurements. Here is a simple process to follow before committing to a purchase:

1. Measure the room length and width using a tape measure. Note both dimensions in centimetres.
2. Subtract clearance space. Allow at least 60 cm of walking clearance on both sides of the bed and 90 cm at the foot if possible.
3. Account for the frame. Bed frames add 5 to 10 cm to the width and length of the mattress. Check the specific frame dimensions before ordering.
4. Sketch your layout. Map out where the bed, wardrobe, and other furniture will sit. A scaled floor plan helps you spot issues before delivery day.
5. Consider door swing and access. Memory foam mattresses are heavy. Make sure your hallways and doorways allow for safe delivery and manoeuvring.

Things to Know

• Australian King mattresses are not the same as US King (also called Eastern King in the US), so imported frames may not fit local mattresses correctly.
• Memory foam mattresses are heavier than innerspring models of the same size. A Queen memory foam mattress can weigh between 25 and 40 kg, so check delivery access and base support.
• Some retailers offer "split King" or "dual King" configurations using two King Singles placed side by side, which allows couples to choose different firmness levels independently.
• Mattress protectors and sheet sets should always be purchased after confirming the exact mattress dimensions from the manufacturer, not just the size label.
• The height (profile) of a memory foam mattress also matters. Taller profiles of 30 cm or more can make fitted sheets harder to keep in place.
• If you are buying a new mattress without replacing your frame, check that your existing frame is rated for memory foam's weight distribution, which differs from innerspring springs.

Ready to Choose Your Mattress Size?

Take your tape measure into your bedroom right now and note down the exact room dimensions. Then use the size table above to match your room size and sleeping situation to the correct mattress. If you are hovering between two sizes, always go larger if your room allows it: you will not regret the extra space, but you will notice the lack of it within weeks.

Once you have confirmed your size, pair your new mattress with a compatible frame and base for the best long-term support and performance.

Frequently Asked Questions

What is the most popular memory foam mattress size in Australia?

The Queen size is the most popular mattress size in Australian households. It fits the majority of master bedrooms, comfortably accommodates two adults, and works with the widest range of base and frame options. It also offers the best balance of sleeping surface and room clearance for typical Australian home layouts.

Can a King Single replace a Queen if I have a smaller bedroom?

A King Single is a practical alternative to a Queen for solo sleepers but is not wide enough for two adults. At 107 cm wide compared to 153 cm for a Queen, the King Single works well for a teenager or a solo adult in a room that cannot fit a larger bed. However, for couples, it would result in a very cramped sleeping experience.

Is a Queen or King better for couples who sleep hot?

A King mattress is generally better for couples who sleep hot, as the additional width reduces body heat transfer between partners. Memory foam retains more heat than other materials by design, so more space between partners helps mitigate this. Look for memory foam models with open-cell construction or gel-infused layers if heat retention is a concern regardless of mattress size.

How much space should I leave around the bed in my bedroom?

Aim for at least 60 cm of clearance on each side of the bed and 90 cm at the foot where possible. This allows you to move comfortably around the room, make the bed easily, and access furniture without obstruction. In particularly narrow rooms, 45 cm on one side can work, but anything less than that makes the space feel and function poorly.

Do memory foam mattresses come in all standard Australian sizes?

Yes, reputable Australian retailers stock memory foam in all five standard sizes: Single, King Single, Double, Queen, and King. Availability across all sizes is now common with both in-store and online retailers. Lead times can vary by size, with King mattresses occasionally having longer wait times due to weight and logistics involved in delivery.

The Bottom Line on What Size Memory Foam Mattress Is Best

There is no single answer that fits every household, but the framework is straightforward: match the mattress size to your room dimensions, your sleeping arrangement, and the clearance you need for daily comfort. For most Australians sharing a bed, a Queen is the practical sweet spot. For those with a spacious master bedroom and a preference for extra room, a King is worth every centimetre.

Take your measurements, review the size comparison table, and consider the full setup including frames, bases, and supporting furniture before committing. A well-chosen mattress paired with the right bedroom setup is one of the most impactful investments you can make in your daily wellbeing.