A Complete Guide to Bed Sizes and Mattress Dimensions

Choosing the right bed size can feel like solving a puzzle - especially when there are so many options out there. 

Whether you’re upgrading from a twin to a queen bed or deciding between a king size and California king, understanding bed sizes and mattress dimensions is key to 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

Twin bed: 38" x 75"

The twin bed, also known as a single bed, is the smallest standard size that measures 38 inches wide and 75 inches long. 

It’s a great option for kids, young teens, or single sleepers who don’t require much space. Twin beds are often used in children's rooms, bunk beds, and smaller guest rooms due to their compact size, making them an excellent space-saving solution.

Twin XL bed: 38" x 80"

A Twin XL bed is a slightly longer version of the standard twin, measuring 38 inches wide and 80 inches long. It's ideal for taller individuals or teenagers who have outgrown a regular twin but still need a compact bed. 

Twin XL beds are commonly found in college dorm rooms due to their space-saving size and extra length.

Full bed: 53" x 75"

Also known as a double bed, a full bed is 53 inches wide and 75 inches 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. Full beds are also great for smaller master bedrooms or guest rooms.

Queen bed: 60" x 80"

The queen-sized bed is one of the most popular bed sizes, measuring 60 inches wide and 80 inches long. It strikes the perfect balance between space and comfort, making it ideal for couples who want room to move without taking up too much space in a bedroom. It’s also a popular choice for guest rooms.

King bed: 76" x 80"

The king-sized bed is the largest standard bed size, coming in at 76 inches wide and 80 inches long. This bed is perfect for couples who want maximum space or for families who like to share their bed with kids or pets. It’s essentially the equivalent of two Twin XL beds side by side.

California King Bed: 72" x 84"

The California King bed is slightly narrower but longer than a standard king, measuring 72 inches wide and 84 inches long. This bed is ideal for taller individuals who need the extra legroom while still providing plenty of space for couples.

Uncommon bed sizes

Aside from the usual twin to California king beds, there are also some less common bed sizes: the split king, Olympic queen, and Alaskan king-sized beds.

Split king: Two 38" x 80" (each)

A split king is essentially two twin XL beds placed together, allowing each sleeper to customize their mattress. This is popular for adjustable beds where partners might have different comfort preferences.

Olympic queen: 66" x 80"

An Olympic queen measures 66 inches wide by 80 inches long, making it slightly wider than a standard queen. This size is less common but works well for couples who need just a bit more width but don’t have room for a king.

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

Alaskan king: 108" x 108"

The Alaskan King is one of the largest bed sizes available, measuring a whopping 108 inches by 108 inches. 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:

Room size vs Bed size: We did the math

You can fall in love with a bed online — but if it swallows your room IRL, it’s not love. It’s poor planning. Here’s a cheat sheet to help you size up responsibly:

• 10' x 10' rooms: Twin, Twin XL, Full beds
  
  

• 10' x 12' rooms: Queen beds
  
  

• 12' x 14'+: King, California king beds

The general rule? You’ll want at least 24 to 30 inches of walking space around your bed so you’re not crab-walking sideways to get to your closet.

What really matters when choosing the right bed dimensions

Beyond the width and length of a bed, you also have to measure up to real life. We’re talking about how you sleep, how you live, and how your room actually works day to day. Because what good is a king-sized bed if it leaves zero room to walk — or worse, to open your wardrobe?

Here’s what to keep in mind beyond the tape measure:

1. Sleeping habits

Are you a starfish sleeper who needs space to stretch like it’s yoga class at 3 a.m.? Or do you curl up like a croissant in one corner of the bed and call it a night?

Let’s explore some scenarios:

• Solo sleeper: If you tend to stay put through the night, a twin or full bed could be your sweet spot. But if you're prone to tossing, turning, or flinging a leg into open space, you’ll likely appreciate the extra room a queen or king bed offers.
  
  

• Couples: Sharing a bed means you need to account for the sleeping styles of both partners. Some partners enjoy sleeping close — until one starts snoring or sleep-dancing. If you both value personal space (or need room for a midnight scroll without elbows knocking), a king or California king gives you that much-needed buffer zone. 
  
  

• Families with kids or pets: If your kids or pets love to join you in bed, a bigger bed isn’t just indulgent — it’s strategic. A king bed makes room for morning cartoons, sleepy toddlers, or pets who think the bed belongs to them. 

Here’s a quick tip for co-sleepers: Lie down side by side and stick your elbows out. If they touch, then it’s time to size up. Your future sleep selves will thank you.

2. Bedroom space

Before you fall in love with that king-sized bed, make sure it fits comfortably in your bedroom. Before you commit, measure your space like you mean it. The goal is to make sure you’re not tiptoeing around your bed like it’s a museum exhibit.

In smaller bedrooms, stick with a twin, twin XL, or full. These sizes are compact enough to give you breathing room for a bedside table. Medium to large spaces open the door to queen or king beds, with plenty of space for dressers, and yes, that modern accent chair you’ve been eyeing.

Our golden rule? Leave at least 24 inches of clearance around the bed. That’s enough to walk, stretch, or reach under the bed for that sock that went rogue.

3. Lifestyle considerations

Here’s the thing about bed sizes: they’re easy to buy for now — but smart to plan for later. Maybe you’re in a one-bedroom apartment today, but planning to move, start a family, or turn that guest room into a home office/guest hybrid in the near future.

If you’re shopping for a guest room, think versatility. A queen bed is a reliable all-rounder — it works for couples, single sleepers, and even the occasional visiting pet. 

If you’re tight on space, a full or twin XL with a pull-out trundle can be a sleek space-saving option.

Expecting a change in household dynamics soon — like a baby, a pet, or a live-in partner? A king bed offers room to grow, both in bodies and bedtime routines. Trust us: you’ll never regret the extra space when life starts happening in your bed (from family snuggles to movie nights to Sunday coffee in pajamas).

4. Budget considerations

Spoiler: Bigger beds = bigger budgets. 

From the bed frame to the mattress, and right down to the fitted sheet that never quite fits, going up in size can stretch your wallet as much as your floor space.

A queen bed often hits the sweet spot — plenty of comfort without sticker shock. But if you’re leaning toward king or California king territory, remember the costs go beyond the bed itself. Think: premium mattresses, larger duvets, and that “why does this king-size pillowcase cost that much?” moment.

That said, a bed is one of the few things you use every single day. And a good one can mean better sleep, better mornings, and better everything. So if it takes a little more upfront investment to get a restful night for years to come, that’s not a splurge — it’s strategy.

Sleep easy with the right bed

Beds are personal. You spend a third of your life in one — or more if you count the doomscrolling and mid-morning coffee rituals. 

So don’t rush the decision. Think about your space, your sleep habits, your lifestyle. And if you’re still torn between Queen and King, ask yourself: do I want more room to move — or more room to live?

Because here, we’re not just measuring beds. We’re measuring comfort per square inch.

Frequently asked questions about bed dimensions

1. Can two people sleep on a full bed?

Yes, but it may feel tight. A full bed is 54 inches wide, giving each person just 27 inches, which is less than a twin. Couples who need more room to stretch and sprawl may prefer a queen or king-sized bed.

2. Do couples sleep better in a bigger bed?

Often, yes. While it depends on individual preferences, King and California king beds offer more room, reducing sleep disruptions and improving quality of rest. But if you like to cuddle, a queen or full bed may still work. 

3. What size bed should I get for my height?

To decide on the best bed size to get for your height, add 6 inches to your height and choose a bed longer than that. For example, if you're 5'9" (69 inches), a twin XL, queen, or king (all 80 inches long) would be suitable.

Don’t forget to also consider whether you’ll be sleeping alone or with someone else when deciding on the final bed dimensions. 

4. Is my bed too big for my room?

Leave at least 24" of walking space around the bed. If your bed dominates the room or restricts movement, then it may be too large. 

Additionally, you may also want to consider whether the size you select allows for various layout preferences, such as the best bed position for Feng Shui. 

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

A queen bed (60 inches wide by 80 inches long) is ideal for guest bedrooms — comfortable for couples and spacious for solo sleepers, without taking up too much room.

6. Is a California king bigger than a regular king?

A California king bed is often misunderstood in terms of its dimensions. A California king is longer (84 inches vs 80 inches) but narrower (72 inches vs 76 inches) than a king bed. It’s great for taller people needing legroom. The difference might not be noticeable for couples who prefer to sleep close together, but if you're someone who likes more space on the sides, the regular king might be a better fit. 

7. What size bed do two single beds together make?

When placed side by side, two twin XL beds equal a king or split king (76 inches wide by 80 inches long), offering flexibility for shared or adjustable sleep setups.