UK Bed Size Guide: Single to Emperor Bed

Choosing the right bed size starts with knowing exactly how much space you're working with. While most of us are familiar with single, double and king size beds, the measurements aren't always as straightforward as they seem, particularly when you're comparing different wooden bed frames.

In the UK, standard bed sizes are based on mattress dimensions, but the complete frame will usually be slightly wider and longer. Understanding that difference can save you from ordering a bed that fits your mattress perfectly but leaves less room around it than you expected.

We've put together this UK bed size guide to help you compare the measurements, understand the differences and find the right fit for your bedroom.

UK Bed Sizes and Dimensions

The table below covers the six mattress sizes available at The Wooden Bed Company, from a standard single to our largest emperor beds.

These measurements refer to the mattress, not the complete bed frame. Emperor mattress dimensions can vary between manufacturers, so always check the exact size before ordering.

One detail worth noticing is that UK king, super king and emperor mattresses are longer than standard singles, small doubles and doubles.

That extra length can be particularly useful for taller sleepers, while the additional width of larger sizes gives couples more room to spread out.

Mattress Size vs Bed Frame Size: What's the Difference?

When you see a bed described as a king size or double, the measurement usually refers to the mattress it's designed to accommodate.

The external dimensions of the bed frame will be larger because the timber surrounding the mattress takes up additional space. How much larger depends on the design. A substantial wooden headboard, a footboard or a frame with wider side rails can all affect the overall footprint.

For example, a standard UK double mattress measures 135 × 190cm. A wooden double bed frame will need to accommodate that mattress, but its complete width and length will depend on how the frame has been constructed.

This distinction matters most when you're working with limited space, such as:

• A bed positioned between two wardrobes or bedside cabinets.
• A frame that needs to fit within an alcove.
• A narrow bedroom where walking space is already restricted.
• A room with doors or drawers that open close to the bed.

From the Workshop: One thing we always recommend checking is the complete size of the bed frame, rather than relying on the mattress dimensions alone. The thickness of the timber, side rails and headboard design can all affect the overall measurements. If you're working with a particularly tight space, our team can help you check the dimensions before you order.

At The Wooden Bed Company, we make our frames from solid European oak and Scandinavian pine, with different styles and designs available across the collection. The exact external measurements will depend on the bed you choose.

Which Bed Size Is Right for Your Bedroom?

There's no single bed size that works for every bedroom. Two rooms with the same floor area can have very different layouts depending on where the doors, windows, wardrobes and other furniture are positioned.

Rather than choosing a bed based on the room's overall dimensions alone, think about how much usable floor space you have and how you'll move around the bed.

Smaller Bedrooms and Guest Rooms

A single bed is often the most practical option for a compact bedroom, particularly when you need to accommodate a desk, wardrobe or other furniture alongside it.

A small double provides an additional 30cm of mattress width compared with a single, without increasing the mattress length. That makes it worth considering for someone who sleeps alone but would appreciate more room.

It's also a popular compromise for guest bedrooms where a full double would take up too much space. If you're choosing between the two sizes for a child's bedroom, our guide to single vs small double beds for children explores the practical differences in more detail.

Double Bedrooms

A standard double is 135cm wide, making it 15cm wider than a small double. It can accommodate two adults, although the amount of personal sleeping space will be more limited than on a king or super king.

For bedrooms where a larger frame would interfere with furniture or leave very little walking space, a double can still be a sensible choice. If the room allows, moving up to a king provides an extra 15cm of width and 10cm of length. It's worth considering both measurements, especially if one or both sleepers are tall.

Larger Bedrooms

King and super king beds are popular choices for couples who want more sleeping space, while emperor beds offer an even more generous mattress area.

However, the biggest bed isn't necessarily the best choice for every large bedroom.

A super king might fit comfortably along one wall but make it difficult to open a wardrobe opposite. Similarly, an emperor bed can look beautifully proportioned in a spacious room, provided there's enough clearance around it for everyday use.

Think about the complete layout, including bedside furniture and access to storage, before deciding how much of the room you'd like the bed to occupy.

Understanding the Differences Between UK Bed Sizes

Sometimes the difference between two bed sizes is smaller than you might expect. In other cases, moving up a size can make a noticeable difference to how much space you have when sleeping.

Here are a few comparisons worth considering before making your decision.

Small Double vs Double

A small double mattress measures 120 × 190cm, while a standard double measures 135 × 190cm.

That additional 15cm of width makes a double a more comfortable option for many couples, although both sizes have the same length.

Small doubles are particularly useful in compact bedrooms, guest rooms and spaces where you want a wider bed for one person without sacrificing too much floor space.

Double vs King

Moving from a double to a king gives you an extra 15cm of width and 10cm of length.

That extra length is one of the most important differences, especially for taller sleepers who may find a standard double restrictive. A king can also provide a little more personal sleeping space for couples without taking up as much room as a super king.

King vs Super King

Both king and super king mattresses measure 200cm in length, but a super king is 30cm wider.

For couples, that's an additional 15cm of sleeping width per person when the mattress is shared equally. If your bedroom has enough space, upgrading from a king to a super king can make a noticeable difference, particularly if you prefer more room to move during the night.

However, that extra width also affects the space available for bedside tables, wardrobes and other furniture. If you're considering making the change, our guide to upgrading from a king to a super king bed explores the practical benefits and considerations in more detail.

Super King vs Emperor

Our emperor mattresses measure 215 × 215cm, compared with 180 × 200cm for a super king. 

That's an additional 35cm of width and 15cm of length, making an emperor a particularly generous option for larger bedrooms. It's worth checking mattress and bedding availability before choosing this size, as emperor dimensions aren't standardised across every UK retailer.

Are European and American Bed Sizes Different?

UK bed dimensions aren't necessarily the same as those used elsewhere in Europe or the United States.

For example, a European double mattress commonly measures 140 × 200cm, compared with the UK standard of 135 × 190cm. Although the difference might sound relatively small, it can prevent the mattress from fitting correctly within a UK double bed frame.

American sizes also follow different measurements and naming conventions. A US queen mattress, for instance, is approximately 152 × 203cm, making it slightly wider and longer than a standard UK king.

If you've purchased a mattress abroad, it's best to work from its exact measurements rather than assuming the size name will match a UK equivalent. This is particularly important when buying a wooden bed with a recessed mattress area, where even a small difference in dimensions can affect the fit.

Can You Get a Wooden Bed Made for a Non-Standard Mattress?

If you already own a European, American or unusually sized mattress, you don't necessarily need to replace it. At The Wooden Bed Company, our bespoke wooden bed service allows you to enquire about a frame made to accommodate non-standard mattress dimensions.

We can also discuss adjustments to the frame height, headboard and other design features if you're working with an unusual bedroom layout.

The most useful starting point is to measure your mattress accurately and share those dimensions with our workshop.

Before You Order: A Bed Size Checklist

Once you've narrowed down your preferred size, there are a few final checks worth making before ordering your wooden bed.

Measure the mattress: Confirm its width, length and depth, especially if you're keeping an existing mattress.

Check the complete frame dimensions: Remember that the external measurements will be larger than the mattress itself.

Allow room to move: Think about access around the bed and whether you'll have enough space to make it comfortably.

Check surrounding furniture: Make sure wardrobes, drawers and bedroom doors can still open fully.

Consider delivery access: Measure narrow staircases, doorways and awkward corners, particularly when ordering a larger bed.

Think about future requirements: If you're planning to keep the bed for many years, consider whether your chosen size will continue to suit your needs.

It's also worth looking at the different frame styles available in your preferred size. A bed with a substantial headboard and footboard may have a different footprint from a simpler platform design, even when both accommodate the same mattress.

Find Your Perfect Size at The Wooden Bed Company

Once you've settled on the right size, the enjoyable part begins: choosing a wooden bed that feels at home in your bedroom.

We make our beds to order in our Yorkshire workshop, using solid European oak and Scandinavian pine. Whether you're furnishing a small guest room or choosing a generous emperor bed for your main bedroom, every frame benefits from the same care and attention to construction.

Our collection includes everything from practical single wooden beds and space-saving small doubles to double beds, king size beds, super king beds and our largest emperor wooden beds.

And because we make our beds ourselves, we're always happy to help if you're unsure about measurements or need something a little different. Explore our wooden bed collection, find the size that suits your space and choose a bed made with the kind of care we'd want for our own homes.