Sizes9 min read
Double vs king size bed: is the bigger bed worth it?
A king is 15 cm wider and 10 cm longer than a double. Shared between two, that takes each of you from less than a child’s bed to a full small single. Your room, your height and your budget decide which one you should buy.
In this guide
- Double vs king size bed: the dimensions side by side
- Is a double bed big enough for two adults?
- Does the extra 10 cm of length matter?
- Will a king size bed fit your bedroom?
- How much more does a king size bed cost?
- When is a double the better choice?
- Is a small double a good alternative?
- Does the frame style change the answer?
- Questions
Key takeaways
- A UK king is 150 × 200 cm and a double is 135 × 190 cm, so the king is 15 cm wider and 10 cm longer.
- Shared between two, a double gives each sleeper 67.5 cm, less than a 75 cm small single. A king gives each of you the full 75 cm.
- The extra 10 cm of length matters if either of you is around 6 ft or taller.
- Allow about 2.8 × 2.8 m of room for a double and 3.0 × 3.0 m for a king.
- At Bedline the step from double to king adds around £30 to most frames, and the ottoman base costs £219 in both sizes.
- For one sleeper, a guest room or a room under about 2.8 m in either direction, a double (or a small double) is the better buy.
Double vs king size bed: the dimensions side by side
UK bed sizes are standard, so these figures hold for any British mattress and any British frame. The king gains on both measurements, 15 cm across and 10 cm in length, and the length is the part most people forget.
| Double | King | |
|---|---|---|
| Width | 135 cm (4 ft 6 in) | 150 cm (5 ft) |
| Length | 190 cm (6 ft 3 in) | 200 cm (6 ft 6 in) |
| Width per person (two sleepers) | 67.5 cm | 75 cm |
| Comfortable room size | About 2.8 × 2.8 m | About 3.0 × 3.0 m |
| Tight but workable | 2.5 × 2.6 m | 2.7 × 2.8 m |
- wider than a double
- +15 cm
- longer than a double
- +10 cm
- more sleeping area
- +17%
Plan around the frame as well as the mattress. Siderails, padding and wings add roughly 5 to 25 cm on each side, depending on the design, and the headboard adds depth at the top. A winged double can take more floor than a plain king.
Is a double bed big enough for two adults?
Split a 135 cm double down the middle and each of you gets 67.5 cm. A UK small single, the size made for a child or a box room, is 75 cm wide. Two adults sharing a double each sleep on less width than a child’s bed.
A king gives each of you the full 75 cm. The gain is 7.5 cm per person. You feel it at the shoulders and elbows, and in how often one of you wakes when the other turns over.
Plenty of couples sleep well in a double for years. It works if:
- You sleep close together and rarely spread out across the mattress.
- One person sleeps in it. On your own, 135 cm is generous.
- It is a guest room that sees a handful of nights a year.
- Neither of you is tall, so 190 cm of length leaves room at your feet.
If one of you is a restless sleeper, or a child or a dog regularly ends up in the bed, the extra 15 cm earns its place every night.
Does the extra 10 cm of length matter?
For tall sleepers it matters as much as the width. A double is 190 cm long, or 6 ft 3 in. Your pillow takes a share of that at the top, and your feet need somewhere to go at the bottom.
As a guide, if either of you is around 6 ft or taller, choose the 200 cm king even if the width suits you. A tall sleeper in a short bed tends to lie diagonally, and that takes width from the person next to them.
Kings and super kings are both 200 cm long. If length is your main reason to move up, a king gives you all of it, and our king vs super king guide covers the next step in width.
Will a king size bed fit your bedroom?
A king needs about 20 cm more floor than a double in each direction. On a floor plan that looks small. In a room where the bed already sits close to the wardrobe, 20 cm can be the gap you squeeze through every morning.
Leave roughly 70 cm of clear floor on any side you walk down, and 90 cm where a wardrobe door or drawer opens into the walkway.
Measure the room both ways
Wall to wall, at floor level. Note radiators, skirting boards and any chimney breast, since each one eats into the space.
Start from the frame
For a king, take 150 × 200 cm and add the frame: roughly 10 to 50 cm across, plus the depth of the headboard. A plain frame adds the least.
Take off the walkways
Subtract 70 cm for each side you walk down and 90 cm where a door or drawer opens. If what is left is narrower than the king frame, choose the double.
Check the way in
Measure the front door, stairs and landing. Every Bedline bed arrives in parts and is assembled in the room, so the headboard is the largest piece you need to get upstairs.
As a rule of thumb, a room of 3 × 3 m or more takes a king comfortably. Down to about 2.7 × 2.8 m, a king still works if nothing opens into the walkway. Below that, the double is the better fit. Our bed size guide lists the room sizes for every UK bed.
How much more does a king size bed cost?
On the frame, less than most people expect. At Bedline the step from double to king adds around £30 to most frames.
| Item | Typical extra for a king |
|---|---|
| Upholstered or divan bed frame | Around £30 (from £20 to £80 depending on the frame) |
| TV bed frame | Around £80 |
| Slatted gas-lift ottoman base | Nothing: £219 in both sizes |
| Mattress added with your bed | A king open coil is £209; the bed page shows every mattress price for each size |
| Bedding | King sets usually cost a little more than double sets |
Our king frames start at £359 for a divan and £399 for an upholstered bedstead. You can pay by card or PayPal, or spread the cost with Klarna.
The ottoman base tips the sums further. It costs £219 under a double and £219 under a king, so the king gives you about 17% more storage under the mattress for nothing extra on the base. Our guide to whether ottoman beds are worth it covers the trade-offs.
Good-value king size frames
Prices shown are for the king frame.
Storage optionsChoose fabric and size
ChesterfieldChoose fabric and size
WingedChoose fabric and sizeWhen is a double the better choice?
Double or king at a glance
Choose a double if
- You sleep alone, or it is a guest room
- Your room is under about 2.8 m in either direction
- You sleep close together and neither of you is over about 6 ft
- Your stairs or landing are tight
Choose a king if
- Two adults share the bed every night
- Either of you is around 6 ft or taller
- Your room is about 3.0 × 3.0 m or larger
- You want more ottoman storage for the same base price
A double is the right bed for a lot of rooms. In a smaller bedroom, a double with a clear walkway on both sides is easier to live with than a king you have to edge around. For one sleeper, 135 cm is plenty, and the money you save on the frame can go towards a better mattress or a taller headboard.
Choose the king if two adults share the bed every night and the room takes it. You gain width and length for around £30 on most frames, and you notice the difference from the first night.
Is a small double a good alternative?
If a double already feels like a squeeze, look at a small double. It measures 120 × 190 cm (4 ft × 6 ft 3 in): 15 cm narrower than a double and the same length.
For one adult it is a generous bed, a third wider than a 90 cm single. For two adults sharing every night it is tight, at 60 cm each. It needs a room of about 2.6 × 2.6 m, or 2.3 × 2.4 m at a squeeze, which makes it a strong choice for a small guest room or a bedroom that also works as a study.
Does the frame style change the answer?
In a borderline room it often decides it. A plain or panelled frame adds a few centimetres to the mattress, while a winged headboard adds width at the head end and a sleigh frame adds length at both ends. A slim king can take less floor than a winged double, so when the room is tight, compare frame sizes as well as mattress sizes.
Height costs you no floor. Our headboards are 54 inches tall as standard, with 60, 72 and up to 79 inches available. If the room points you to a double, a taller headboard still gives the bed presence without making it any wider.
The verdict
If two adults share the bed and your room is about 3.0 × 3.0 m or larger, a king is worth it: each of you gets 75 cm instead of 67.5 cm, you gain 10 cm of length, and at Bedline the frame costs around £30 more on most designs. For one sleeper, or a room under about 2.8 m in either direction, a double with space around it is the better choice.
Questions people ask
What is the difference between a double and a king size bed?
A UK king is 150 × 200 cm and a double is 135 × 190 cm. The king is 15 cm wider and 10 cm longer.
Is a king worth it over a double?
For two adults in a room of about 3 × 3 m or more, usually yes: each of you gets 75 cm instead of 67.5 cm, plus 10 cm more length. For one sleeper or a smaller room, a double is enough.
Is a double bed big enough for two adults?
It works for couples who sleep close together, but each person gets 67.5 cm, less than a 75 cm small single. Restless or tall sleepers are more comfortable in a king.
What size room do you need for a king size bed?
Allow about 3.0 × 3.0 m to walk round a king comfortably. About 2.7 × 2.8 m is workable if no wardrobe door or drawer opens into the walkway.
How much longer is a king than a double?
A king is 10 cm longer: 200 cm (6 ft 6 in) against 190 cm (6 ft 3 in) for a double.
Will a double mattress fit a king size frame?
No. A king frame is made for a 150 × 200 cm mattress, so a 135 × 190 cm double would leave gaps at the sides and the foot. Buy the mattress to match the frame.
About Bedline
Bedline makes upholstered beds, ottoman beds and TV beds to order in Britain, in six UK sizes and 72 colours, and delivers them free to the UK mainland. Our guides are written by the team who help customers choose their beds every day on WhatsApp, so they answer the questions we are actually asked.
