Long Single vs King Single Mattress: 15 cm Size Difference

The real decision between a Long Single vs King Single mattress is therefore not about length.

It is about whether you would rather have more room on the mattress or more room in the bedroom.

If you need extra length but want to keep the bed relatively narrow, the 92 cm-wide option can make a lot of sense.

If you have enough room and prefer more space to move around in bed, a King Single may be the better fit.

Before deciding, it is worth looking beyond the size chart. The bed base, room layout, fitted sheets and even the way you sleep can all affect which size works better.

Long Single vs King Single Size Comparison

Using the mattress sizes currently listed by Simply The Best Bedding, which are Australian standard sizes:

For context, a standard Single in the Simply The Best Bedding range measures 92 × 188 cm.

That gives us a simple way to understand all three sizes:

So the narrower option is essentially about gaining length without gaining width.

A King Single gives you the longer sleeping surface plus extra room from side to side.

The Difference Is Width, Not Length

The names probably create more confusion than the measurements themselves.

“Long Single” makes it sound as though length is its defining advantage.

“King Single” sounds as though it should be both wider and longer.

In the Simply The Best Bedding range, however, both are 203 cm long.

If your current Single mattress feels too short, either a Long Single or King Single gives you additional length.

Once you look at it that way, the choice becomes much easier.

How Much Difference Does 15 cm Actually Make?

Fifteen centimetres sounds fairly minor when you see it in a mattress specification.

Across the full 203 cm length of the bed, though, it adds around 0.30 square metres of sleeping surface.

That means the King Single provides approximately 16% more mattress area than the Long Single using Simply The Best’s listed dimensions.

For a sleeper, the extra width may provide more space to:

But the bedroom has to give up those same 15 centimetres.

That can affect:

In a generous room, 15 cm may barely register.

In a compact bedroom, guest room or teenager’s room, it can make a noticeable difference to the layout.

Try This Before You Decide

Get a tape measure and mark out 92 cm across the floor where the bed will sit.

Then extend it to 107 cm.

That extra strip represents the difference between the two mattress sizes.

It is a simple test, but it turns an abstract measurement into something you can actually see.

Expert Commentary: We Asked Our Mattress Team

To go beyond the measurements, we asked our internal mattress experts how they approach the Long Single vs King Single decision with customers in the showroom.

1. How Do You Explain the Difference to Customers?

The first step is to explain the measurements of both sizes and, where possible, show customers the sizes physically in the showroom.

The Long Single is displayed as part of a King configuration, which also helps demonstrate how the dimensions work in practice.

2. Does the Extra 15 cm of King Single Width Feel Noticeable?

For a larger-framed person, the difference can be noticeable. For a smaller-framed sleeper, the additional width may be less significant.

3. Who Usually Chooses Long Single and Who Chooses King Single?

It is relatively uncommon for the showroom to sell a Long Single as a standalone conventional bed size.

Where room permits, many customers choose King Single, particularly when the price is the same between the two sizes.

The narrower size may be selected because a customer already has a matching base or an adjustable-bed configuration requiring that size.

Bedframe availability can also influence the decision. King Single frames and matching bedroom furniture may be easier to source.

4. What Common Misunderstandings Do Customers Have?

A common misunderstanding is believing that Long Single and King Single are the same size.

Customers also sometimes assume that two King Singles make a standard King, which is not the same configuration as using two Long Singles.

5. What Is the Practical Rule of Thumb?

Long Single vs Standard Single

A Long Single is particularly useful when a standard Single gives you enough width but not enough length.

The Simply The Best dimensions are:

Moving from a standard Single to a Long Single therefore gives you approximately 15 cm of additional length without increasing the width.

That makes the Long Single an interesting middle ground.

You gain more legroom without automatically giving more of the bedroom to the bed.

For rooms where every centimetre matters, that can be a practical advantage.

Long Single vs King Single for a Tall Sleeper

If height is the reason you are changing mattress size, do not assume you automatically need a King Single.

Both Long Single and King Single provide the same 203 cm length in the Simply The Best range.

Which Is Better for a Teenager?

Both sizes can work well for a teenager.

A King Single provides the longer 203 cm sleeping surface plus additional width.

The narrower option provides the same length while keeping the mattress at 92 cm wide.

The right choice often comes down to what else needs to fit into the bedroom.

Teenagers’ rooms may also need space for:

If the room is generous, the additional sleeping width of a King Single may be worthwhile.

If space is already tight, the narrower size can provide the longer sleeping surface without taking another 15 cm from the rest of the room.

There is no universal answer.

It depends on how they sleep and how the room is used when they are awake.

What About an Adult Sleeping Alone?

Either size can work for an adult solo sleeper.

The narrower size offers the 203 cm length while keeping the mattress relatively compact.

A King Single provides the same length with more room from side to side.

Someone who sleeps fairly still may find the 92 cm-wide option gives them enough personal space.

Someone who tends to spread out or regularly changes position may appreciate the additional width of a King Single.

A larger mattress is not automatically a more comfortable mattress.

How a mattress feels also depends on factors such as:

It can therefore help to make the buying decision in two stages. You can also compare the current Simply The Best mattress range once you know which physical size suits the sleeper and room.

First: decide how much physical sleeping space you need.

Second: compare the mattress constructions and comfort feels available in that size.

That is more useful than simply buying the biggest mattress that fits the room.

Once you know which physical size suits the sleeper and the room, the next question is which mattress construction and comfort feel to choose. Our broader guide to choosing the best mattress for your body, bedroom and sleep style looks at support, comfort, sleep position and other buying considerations beyond dimensions.

For a more step-by-step approach, you can also read our five expert tips for choosing the right mattress. That guide is useful once you have narrowed down the size and want to compare how different mattresses may feel and perform.

Which Is Better for a Guest Room?

A guest room presents a slightly different decision.

You may want enough length to accommodate taller visitors, but the room may also need to function as an office, study or general-purpose space when nobody is staying overnight.

In that situation, the narrower footprint can be useful.

If the room is used primarily as a bedroom and has enough floor space, a King Single provides guests with additional sleeping width.

Again, there is no automatic winner.

Think about how often the bed is used, who is likely to sleep there and what the room needs to do the rest of the time.

If the room is being furnished for visitors or short-stay accommodation, mattress size is only one part of the decision. Our guide to guest-bedroom mattress choices for Perth Airbnb hosts looks at size alongside durability, comfort and the practical needs of different guests.

That can be particularly useful when deciding whether the extra width of a King Single is worth giving up floor space that could otherwise be used for luggage, storage or other furniture.

Which Is Better for a Small Bedroom?

If floor space is tight, the 92 cm-wide option has an obvious advantage.

It gives you the same 203 cm sleeping length while using 15 cm less mattress width than a King Single in the Simply The Best Bedding range.

Mattress Size Is Not Necessarily the Total Bed Size

A mattress measuring 92 cm or 107 cm wide does not mean the complete bed will occupy exactly that amount of floor space.

Depending on the design, the bed may also include:

These can extend beyond the mattress.

So if you are working with a tight room, measure the external dimensions of the complete bed, not only the mattress.

If you are planning the entire room rather than choosing the mattress in isolation, our guide to planning your bedroom around the mattress first explains how bed size, furniture placement, walking space and finished bed height work together.

This matters because a mattress can fit on paper and still make the room difficult to live in once bedside tables, wardrobes, drawers and circulation space are taken into account.

A mattress can technically fit into a room while still making the room awkward to use.

That is why the complete footprint matters.

Width and length are not the only measurements worth checking. Mattress depth can also change the finished bed height, sheet fit and how the mattress works with the base, so our guide to mattress thickness in Australia is a useful companion to this size comparison.

Looking at width, length and thickness separately gives you a much clearer picture of how the complete bed will fit and function in the room.

Will a Long Single Mattress Fit a King Single Base?

These two mattress sizes should not be treated as interchangeable simply because they have the same length.

The key difference is their width.

A mattress and base should be matched according to their actual dimensions.

Putting a narrower mattress onto a base intended for a wider mattress can leave unwanted space around the sleeping surface.

Trying to fit a wider mattress onto a narrower frame creates the opposite problem.

If you already own the base, measure it before ordering the mattress.

If you are buying the mattress and base together, confirm that they are designed to work together.

Are Australian Mattress Sizes Always Exactly the Same?

Do not rely on the size name alone when compatibility matters.

Mattress dimensions are product specifications, so it is worth checking the measurements supplied for the particular mattress, base, frame and bedding you are buying.

This is particularly important when you are:

Throughout this guide, we are using the current Simply The Best Bedding dimensions of 92 × 203 cm for Long Single and 107 × 203 cm for King Single.

If you are buying a different product or matching an existing setup, check the measurements rather than assuming the size label tells you everything.

Is a Long Single the Same as a Single XL?

You may come across terms such as Long Single and Single XL while comparing bedding products.

Rather than assuming differently named sizes are identical, look at the actual width and length listed for the product.

For Simply The Best Bedding mattresses, the relevant longer Single size is listed as Long Single at 92 × 203 cm.

When matching a mattress with an existing frame, base, sheet or protector, the measurements are more useful than the terminology.

What About Sheets and Mattress Protectors?

Do not assume ordinary Single linen will automatically fit a Long Single mattress.

At Simply The Best Bedding, a standard Single and the longer 92 cm-wide size share the same width, but the longer size is approximately 15 cm longer.

That additional length can matter with fitted products.

Mattress depth matters too.

A fitted sheet can have the correct width and length but still be too shallow for a deeper mattress.

The same principle applies to fitted mattress protectors. If you are comparing protector materials, waterproofing and fit as well as size, our mattress protector guide for Perth buyers covers the practical points to check before choosing one.

For a Long Single in particular, it is worth confirming the stated length and skirt depth rather than assuming ordinary Single fitted bedding will stretch to fit.

Long Single vs King Single for an Adjustable Bed

This is one area where general rules can easily lead you in the wrong direction.

The 92 × 203 cm size is often discussed in connection with individual and split sleeping arrangements, but that does not mean every adjustable bed requires that mattress size.

King Single adjustable beds exist too.

For example, the Simply The Best Bedding Grand Posture VitaLift Adjustable Bed has a published sleeping surface of 107 × 203 cm, which matches the King Single dimensions currently listed in the Simply The Best mattress range.

Check:

The adjustable base should determine the required mattress dimensions. If you are comparing complete setups, you can also view the current bed bases available from Simply The Best Bedding.

If you are choosing the mattress and adjustable base together, our detailed guide to the best mattress for an adjustable bed in Australia explains mattress sizing, flexibility, construction and base compatibility in more detail.

That guide is especially relevant when deciding between Long Single and King Single because the mattress must match the actual sleeping surface of the adjustable base rather than a general assumption about adjustable-bed sizing.

That is much safer than choosing Long Single or King Single based on a general rule.

If an adjustable bed is being selected as assistive technology, the Australian NDIS guidance on higher-risk assistive technology specifically lists adjustable beds and explains that written advice is required when buying or renting higher-risk assistive technology. That is another reason to confirm the exact base, mattress size and compatibility requirements rather than relying on a general size rule.

Do Two Long Singles Make a King?

This question often comes up when customers are considering a split-bed arrangement.

Simply The Best Bedding follows Australian standard mattress sizing, and the simple answer is yes: two Long Single mattresses placed side by side are the same overall size as a standard Australian King mattress.

That equivalence applies when the mattresses and bed system follow these Australian standard dimensions. It is still important to check the dimensions of your existing bed frame or base.

Some furniture retailers sell imported frames made to European or other international sizing, which may differ from Australian standard dimensions.

Consider:

Choose components that have been designed to work together wherever possible.

What If Neither Size Fits Your Room or Base?

Sometimes the real answer is neither.

You might be replacing a mattress on a non-standard frame, working with unusual room dimensions or trying to match an existing piece of furniture.

In those situations, forcing a standard Long Single or King Single into the space may not be the best approach.

Simply The Best Bedding provides a custom mattress enquiry for customers who need to discuss requirements outside the usual standard-size selection.

Write down the required width, length and any other relevant restrictions, then confirm what can be made or supplied for the setup.

Long Single or King Single: A Simple Decision Guide

Still undecided?

Start here.

There is no universal winner in a Long Single vs King Single comparison.

Think Beyond the Mattress Size

One of the easiest mistakes when buying a mattress is treating size as a single number.

In reality, the mattress is only one part of the decision.

Think about five things together.

1. The Sleeper

How much room do they actually use?

2. The Bedroom

How much space can reasonably be given to the bed?

3. The Base or Frame

Does it match the mattress dimensions?

4. The Bedding

Can you get fitted sheets and protectors that fit properly?

5. The Mattress Itself

Which construction and comfort feel suits the sleeper?

Looking at these factors together gives you a much better chance of getting the purchase right.

These are not better or worse versions of the same mattress size.

They solve slightly different space problems.

A Practical Four-Step Test Before You Buy

If you are still choosing between the two sizes, try this at home.

Step 1: Mark Out the Long Single

Use masking tape or another temporary marker to create a rectangle measuring:

That represents the current Simply The Best Bedding 92 × 203 cm dimensions.

Step 2: Add the King Single Width

Extend the width by 15 cm to:

Now you can see exactly what the King Single adds.

Step 3: Use the Room Normally

Do not just stand back and look at the outline.

Step 4: Think About the Sleeper

Would they genuinely appreciate the extra width?

If the answer is yes and the bedroom still works comfortably, the King Single may be worth considering.

If the additional width makes the room awkward and the main requirement is extra length, the narrower size may make more sense.

Compare the Sizes and Mattress Feel Separately

Measurements help you decide how much mattress you need.

They cannot tell you how the mattress itself will feel.

For broader sleep comfort, Healthdirect’s sleep guidance recommends a comfortable bedroom and comfortable bedding. Mattress size is only one part of that environment, so it still makes sense to assess both the physical dimensions and the comfort feel separately.

Simply The Best Bedding is a Western Australian mattress manufacturer based in Malaga.

The business was established in 2007 and states that its team brings more than 39 years of bedding-industry experience.

If you are deciding between Long Single and King Single, comparing options in person lets you answer two different questions:

Keeping those questions separate is useful.

A King Single in the wrong comfort feel is not automatically a better choice than a Long Single mattress that suits your preferences.

Likewise, the mattress that feels best during a trial still needs to fit properly into your room and onto the correct base.

Simply The Best Bedding’s factory showroom is located at 391 Victoria Road, Malaga, WA 6090. For more practical mattress and sleep buying guides, visit the Beducation.

Frequently Asked Questions About Long Single vs King Single Mattresses

What Is the Difference Between a Long Single and King Single Mattress?

In the Simply The Best Bedding range, both are 203 cm long. A Long Single is 92 cm wide and a King Single is 107 cm wide, so the King Single provides an additional 15 cm of width.

Is a King Single Longer Than a Long Single?

No. In the Simply The Best Bedding range, both Long Single and King Single mattresses are 203 cm long. Their main difference is width.

How Much Wider Is a King Single Than a Long Single?

Using Simply The Best Bedding’s current dimensions, a King Single is 15 cm wider, at 107 cm compared with 92 cm for a Long Single.

How Much Bigger Is a King Single Than a Long Single?

Using the listed dimensions, a King Single provides approximately 16% more mattress surface area than a Long Single. The additional area comes from the extra width because both mattresses are the same length.

Is a Long Single Suitable for an Adult?

It can be. A Long Single provides 203 cm of length while maintaining a relatively narrow 92 cm width in the Simply The Best range. Whether that width feels spacious enough depends on the individual sleeper.

Is a King Single Suitable for an Adult?

It can be a practical choice for a solo adult who wants more width and has enough bedroom space. It provides the same 203 cm length as a Long Single but increases the width to 107 cm in the Simply The Best Bedding range.

Is a Long Single the Same as a Standard Single?

No. At Simply The Best Bedding, both are 92 cm wide, but the standard Single is 188 cm long while the Long Single is 203 cm long.

Is a Long Single the Same as a Single XL?

You may see different terminology while shopping. Rather than assuming two differently named products have identical dimensions, compare their actual width and length. Simply The Best Bedding lists its longer Single mattress size as Long Single at 92 × 203 cm.

Can a Long Single Mattress Go on a King Single Base?

They are different widths and should not be assumed to be interchangeable. Match the mattress to the actual sleeping-surface dimensions of the base.

Do Standard Single Sheets Fit a Long Single Mattress?

Not necessarily. A Long Single is longer than a standard Single in the Simply The Best Bedding range, so check the width, length and skirt depth of fitted sheets and mattress protectors before buying.

Are Long Single Mattresses Used on Adjustable Beds?

They can be, but adjustable beds are not limited to Long Single sizing. The Simply The Best Bedding VitaLift, for example, has a 107 × 203 cm sleeping surface. Always follow the dimensions and mattress-compatibility requirements of the actual adjustable base.

Do Two Long Singles Make a King?

Yes. Using the Simply The Best Bedding dimensions, two Long Single mattresses at 92 × 203 cm each placed side by side create an overall sleeping surface of 184 × 203 cm, matching a standard Australian King mattress. If you are using an existing or imported frame, however, check the actual mattress, base and frame dimensions before purchasing because non-standard sizing can differ.

Which Is Better, Long Single or King Single?

Neither is universally better. The narrower size makes more sense when you need the 203 cm length while preserving bedroom width. A King Single is worth considering when you have enough floor space and want an additional 15 cm of sleeping width.

Long Single vs King Single: The Bottom Line

A Long Single and King Single are easier to compare once you ignore the names and look at what actually changes.

The length stays the same.

The King Single adds 15 cm of width, giving you approximately 16% more sleeping surface.

Choose the narrower 92 cm-wide option when your priority is extra length without unnecessarily increasing the bed’s footprint.

Consider a King Single when you have enough room and would genuinely benefit from more space from side to side.

Before buying, measure the room, check the complete bed footprint, confirm the base dimensions and think about how much sleeping space you actually use.