A Complete Guide to Bed Sizes and Mattress Dimensions

Choosing the right bed size can feel like solving a puzzle — especially with so many options out there. 

Whether you’re upgrading from a single to a double bed or deciding between a king and super king, understanding UK bed sizes and mattress dimensions is key to achieving a good night’s sleep. 

Let’s walk through everything you need to know about bed sizes so you can find the perfect fit for your space and comfort.

Standard bed sizing guide

Single bed: 90 cm x 190 cm

The single bed is the most compact standard size in the UK. Measuring 90 cm wide by 190 cm long, it’s perfect for children, teens, and solo sleepers with limited space.

You'll often find single beds in children's rooms, guest rooms, and studio apartments. They also work great in smaller guest rooms due to their compact size.

Small double (three-quarter) bed: 120 cm x 190 cm

The small double, also known as a three-quarter bed, measures 120 cm wide and 190 cm long. It offers more room than a single without taking up as much space as a standard double.

It's ideal for solo sleepers who want more space to stretch out or for couples in small bedrooms.

Double bed: 134.5 cm x 190.5 cm

Also known as a double bed, a double bed is 134.5 cm wide and 190.5 cm long. It offers more width than a twin or twin XL, making it a good option for single sleepers who like to stretch out or couples who don’t mind a tighter fit. Double beds are also great for smaller master bedrooms or guest rooms.

Double bed: 135 cm x 190 cm

A standard double bed measures 135 cm wide and 190 cm long. It's a good middle-ground option for solo sleepers who prefer more room or couples who are okay with a snug fit.

Double beds are a popular choice for smaller master bedrooms or guest rooms.

King bed: 150 cm x 200 cm

The king-sized bed is a luxurious upgrade, offering more length and width than a double. Measuring 150 cm wide and 200 cm long, it’s great for couples who like a bit more space. It also suits taller individuals who find standard beds too short.

Also, a UK king is slightly smaller than a US king, so double-check when ordering bedding online.

Super king bed: 180 cm x 200 cm

The largest standard bed size in the UK, the super king measures a spacious 180 cm wide by 200 cm long. This is the ultimate in sleeping comfort, perfect for couples, co-sleeping families, or anyone who values extra space in bed.

Uncommon bed sizes

While not as widely available, these sizes can be worth considering for specific needs.

Emperor bed: 200 cm x 200 cm

An Emperor bed offers even more space than a super king, measuring 200 cm in both width and length. It’s a popular luxury choice for large bedrooms and those who co-sleep with children or pets.

Small single bed: 75 cm x 190 cm

Great for toddlers transitioning from a cot, small singles measure just 75 cm wide. They're often used for guest beds or bunk beds where floor space is tight.

However, finding mattresses, bedding, and bed frames for this size can be more challenging since it’s less commonly available.

Alaskan king: 274 cm x 274 cm

The Alaskan King is one of the largest bed sizes available, measuring a whopping 274 cm by 274 cm. This square-shaped bed provides an incredible amount of sleeping space and is perfect for those who want to go all out on comfort and luxury.

If you have a large master bedroom and want maximum sleeping space, the Alaskan King delivers. It’s perfect for families who co-sleep with children or pets, allowing everyone to sleep comfortably without feeling crowded.

Because of its massive size, it's often custom-made, and finding mattresses and bedding can be a challenge.

Here’s an overview of all the bed sizes and dimensions:

Factors to consider when picking a bed size

Choosing the right bed size isn't just about comfort; it's also about making sure the bed fits your lifestyle, space, and needs. Here are key factors to consider when making that all-important decision:

1. Sleeping habits

Your personal sleep style plays a significant role in determining what bed size is best for you. Do you like to stretch out, or do you sleep curled up in a corner? Are you sharing the bed with a partner, kids, or even pets? Let's dive deeper into these scenarios:

• Solo Sleeper: If you're a solo sleeper who tends to stay in one spot, you might be perfectly comfortable with a single or small double bed. However, if you toss and turn throughout the night, or if you like to sprawl out like a starfish, you’ll likely appreciate the extra room a double or king bed offers.
  
  

• Couples: Sharing a bed means you need to account for the sleeping styles of both partners. Some couples enjoy being close together, making a double bed a popular choice. But if both partners like their space, or if one is an active sleeper who tosses and turns, a king or super king is ideal.
  
  

• Families with kids or pets: If your kids or pets love to join you in bed, a larger bed like a super king or emperor is the way to go. This gives everyone room to spread out without feeling cramped. 

Here’s a quick space check tip: If you’re planning to share a bed and don’t want your partner too close for sleeping comfortably, get your partner to lie beside you on the mattress and keep your elbows facing outwards. You’ll know that you’ll have enough room if your elbows don’t touch!

2. Bedroom space

Before you fall in love with that king-sized bed, make sure it fits comfortably in your room. Measuring your space is crucial because even the comfiest bed can become a headache if it leaves no room for anything else.

For smaller bedrooms, a single or small double bed is often the best choice. These sizes save space while still providing a comfortable sleep environment. If you’re working with a more generous room size, double or king beds could be ideal.

Aside from the bed itself, you’ll need to factor in other essential bedroom furniture like your bedside tables, dressers, and possibly a wardrobe or armchair.

A good rule of thumb is to leave at least 60 cm of walking space around the bed. That way, your bedroom won’t feel cramped or difficult to navigate.

3. Lifestyle considerations

Think about how your lifestyle or living arrangements might change in the near future. Are you planning to move to a bigger home or have children? Are you furnishing a guest room that might accommodate couples or single sleepers?

If you’re furnishing a guest room, consider who will be using it. A double bed tends to be the best of both worlds, as it’s large enough for couples but not too massive for a single sleeper. If you often host guests with different needs, a single bed or even a small double could be a smart, space-saving choice.

If you’re planning to start or expand your family, you might want to opt for a larger bed size now. A king bed gives you room to grow, whether that means welcoming children or furry friends into your sleeping space.

4. Budget considerations

Larger beds often come with larger price tags, not only for the bed frame but also for the mattress, bedding, and accessories. Keep in mind that while upgrading to a larger bed may feel luxurious, it could stretch your budget more than anticipated.

Bedding also tend to cost more as the bed size increases, so be sure to factor these additional costs into your decision.

However, consider that a bed is a long-term investment in your comfort and health. Spending a bit more on a bed that fits your needs and lifestyle could be worth it in the long run. A larger bed that provides quality sleep might save you from tossing and turning on a bed that's too small.

Sleep easy with the right bed

Choosing the right bed size is more than a numbers game — it’s about matching your comfort, space, and lifestyle. Whether you're outfitting a compact guest room or upgrading to a luxurious super king, understanding bed sizes helps you make an informed, confident choice.

Now that you’ve got all the details, it’s time to pick the perfect fit — and enjoy many blissful nights ahead.

FAQs

1. Can two people sleep on a double bed?

Yes, two people can sleep on a double bed (135 cm x 190 cm / approx. 53" x 75"), but it may feel tight. Each person would get just 67.5 cm of space — narrower than a standard single bed.

While it can work for short-term stays or couples who like to snuggle, a king (150 cm / 59") or super king (180 cm / 71") offers significantly more room and comfort for two sleepers.

2. What bed size should I get for a guest room?

A double bed (135 cm x 190 cm / 53" x 75") is a popular and practical choice for guest rooms — roomy enough for two adults yet compact enough to fit comfortably in most spaces.

If your guest room is smaller, consider a double bed for solo sleepers or short visits. If space isn’t an issue and you want to offer luxury, a king or super king can elevate the experience.

4. What is the biggest bed size available?

In the UK, the Emperor bed is one of the largest standard sizes, measuring 200 cm x 200 cm (approx. 79" x 79"). It’s luxurious, spacious, and perfect for couples who want plenty of room to stretch out.

In the US, the Alaskan King takes the crown — a massive 274 cm x 274 cm (108" x 108") — great for co-sleeping families or ultra-large bedrooms.