UK Bed Sizes Explained: Single, Double, King and Super King

Standard UK mattress sizes are: single 90cm x 190cm (3ft x 6ft3), small double 120cm x 190cm (4ft x 6ft3), double 135cm x 190cm (4ft6 x 6ft3), king size 150cm x 200cm (5ft x 6ft6) and super king 180cm x 200cm (6ft x 6ft6). These measurements refer to the mattress. The bed frame around it will always be larger, often by 10cm to 25cm in each direction depending on the headboard and side rails.

Knowing the mattress size is only half the job. To choose well, you also need to know how much floor space the frame takes, how much walking room to leave, and which size truly suits the people sleeping in it. This guide covers all of that so you can browse our modern beds UK sale range, and the wider modern bedroom furniture UK collection around it, knowing exactly what will fit.

UK Bed Sizes at a Glance

One point catches many people out: UK and European sizes are not the same. A European double is commonly 140cm x 200cm, while a UK double is 135cm x 190cm. If you buy a frame designed to UK sizes, always pair it with a UK sized mattress so it sits snugly without gaps or overhang. Our modern mattresses UK range is made to standard British sizes for exactly this reason.

Single Beds

A single gives one sleeper 90cm of width, which is enough for most children and teenagers. Adults who sleep alone can manage on a single, though many find a small double more comfortable for turning over.

Singles are the natural choice for box rooms, which in many British homes measure around 2m x 2.5m or smaller. In a room that size, a single placed against the wall leaves floor space for a desk or a small chest of drawers. Taller teenagers should be considered carefully: at 190cm long, a standard single can feel short for anyone over about six feet once pillows are in place.

Small singles at 75cm wide are mainly found on bunk beds and children’s beds. Check bedding carefully, as standard single sheets will be loose.

Small Double Beds

The small double, sometimes called a three quarter bed, is the overlooked middle ground. At 120cm wide it gives a single adult generous space without the footprint of a full double. It works well in narrow rooms, studio flats and guest rooms that double as studies.

Couples can share a small double, but each person has only 60cm of width, which is narrower than a single. For regular shared use, most couples are more comfortable on a double or larger.

Double Beds

The double is the most familiar size in British homes. At 135cm wide, each partner has 67.5cm, which is less than a single bed each. Many couples sleep happily on a double for years, especially if both are of average build and neither sleeps restlessly.

A double fits comfortably in most standard UK bedrooms. A useful rule of thumb is to allow at least 60cm of clear floor around the three open sides of the bed so you can make it and walk past easily. For a double frame of around 150cm x 205cm, that means a room of roughly 2.7m x 2.65m is a comfortable minimum, though people do make smaller rooms work by pushing one side against a wall.

King Size Beds

A king size adds 15cm of width and 10cm of length compared with a double. That may not sound like much on paper, but in practice the extra length is what taller people notice first, and the extra width makes a clear difference to couples who disturb each other in the night.

King size frames are typically around 165cm to 175cm wide and 210cm to 220cm long. They suit main bedrooms in most modern houses, though in smaller new build master bedrooms it is worth measuring before you commit. For a full breakdown of frame, mattress and room measurements, see our guide to UK king size bed dimensions for frame, mattress and room.

Super King Beds

At 180cm x 200cm, a super king gives each partner 90cm, which is the same as having a single bed each. It is the size to consider if children regularly climb in during the night, if a dog shares the bed, or if one partner is a light sleeper.

A super king frame can easily reach 195cm or more in width, so it needs a generous room. Think carefully about access too. Many super king mattresses arrive rolled or are flexible enough to bend, but rigid headboards and long side rails still need to make it up narrow staircases and round tight landings. Measure your stairs, doorways and any turns before ordering.

How to Measure Your Room Properly

Measuring well takes ten minutes and saves a great deal of frustration later.

1. Measure the full room wall to wall in both directions, at floor level.
2. Note obstacles: radiators, sockets, window sills, built in wardrobes and the swing of the door.
3. Find the frame dimensions of the bed you like, not just the mattress size. Headboards and footboards add length.
4. Mark it out on the floor with masking tape. Walk around it, open the wardrobe and the door, and see how it feels.
5. Allow for bedside storage. Most bedside tables are between 40cm and 50cm wide, so add that to each side you plan to use.

Our article on bedside table measurements for UK bedrooms explains how to match table height to your mattress so everything sits at a comfortable reach.

Choosing the Right Size for Your Household

Room size sets the upper limit, but the people sleeping in the bed should decide the final choice.

• Tall sleepers should prioritise length. King and super king beds are 10cm longer than doubles, which matters more than width for anyone over about 6ft.
• Restless sleepers benefit from width. If one partner moves a lot, stepping up from a double to a king often helps both sleep better.
• Single adults can comfortably choose a small double or double, depending on room size.
• Growing children can move from a single to a small double in their teens if the room allows.

Mattresses and Bedding

Once you know your size, buying the right mattress and bedding becomes straightforward. Always match the mattress to the frame size exactly. A mattress that is too small slides and leaves gaps. One that is too large will not sit flat inside the frame.

Check mattress depth as well. Deeper mattresses sit higher and may need deep fitted sheets. They also change how tall the bed feels, which affects bedside table height and how easy it is to get in and out. If you are unsure, measure your current mattress depth and use it as a reference point.

Common Sizing Mistakes to Avoid

• Measuring only the mattress size and forgetting the frame adds length and width.
• Forgetting the door swing, which can clip the corner of a large bed.
• Mixing UK and European sizes between frame and mattress.
• Ignoring access on stairs and landings for larger frames and headboards.
• Choosing by habit rather than need. Many couples who have always had a double find a king makes a real difference.

Bringing It All Together

The right bed size balances the room, the people and the way you live. Measure carefully, mark it out, and choose the largest size that still leaves you comfortable walking space. Our frames come in every standard UK size and a wide choice of finishes, from upholstered fabric to wood, metal and leather.

You can explore everything we offer for the bedroom and the rest of the home at Furniture in Fashion, with free delivery to most UK mainland postcodes. Returns are available up to 30 days.

Frequently Asked Questions

What is the difference between a UK double and a European double?

A UK double mattress measures 135cm x 190cm, while a European double is commonly 140cm x 200cm. Always match the mattress to the size the frame was made for.

Is a king size bed much bigger than a double?

A king size is 15cm wider and 10cm longer than a double. The extra length helps taller sleepers, and the extra width makes a noticeable difference for couples.

What size bed fits in a box room?

Most box rooms suit a single bed, and some can take a small double if the bed is placed against a wall. Measure the room and mark out the frame before deciding.

How much space should I leave around a bed?

Around 60cm of clear floor on each open side is a comfortable guide. It gives enough room to walk past, make the bed and open drawers.

Do bed frames come in the same sizes as mattresses?

Frames are named after the mattress they hold, but the frame itself is always larger. Check the external dimensions of the frame before measuring your room.