The City Mattress Blog

The Ultimate Guide to Choosing a Bed Size


The Ultimate Guide to Choosing a Bed Size

Chances are, you’ve been sleeping on the same bed for years. But, now, it’s time for a change. Maybe your old mattress is starting to sag in the middle, or you’re ready for an upgrade. Whatever the reason, choosing a new bed is a big decision — literally. But choosing from the many mattresses available doesn’t have to be like a bad dream. With some research, you can find the perfect bed for your needs and sleep easily. This guide will walk you through everything you need to know about choosing the right bed size for your needs.

Before You Buy 

When shopping for a new mattress, one of the most important decisions you’ll make is choosing the right bed size. Sure, choosing between innerspring or memory foam mattresses is important too. But getting the right bed size is key to ensuring you’ll be comfortable and get a good night’s sleep. The last thing you want is to end up with a bed that’s too small or too large for your bedroom or the people who will be using it. Let’s explore two main things you need to keep in mind before you make your purchase.

1) Measure Your Bedroom 

The first step is to take measurements of your bedroom to see how much space you have to work with. You’ll need to know the room’s dimensions to narrow your search to mattresses that will fit. It’s important at this stage to decide where the bed will go. If you have a smaller bed pushed up against a wall, you will have more options, even in less spacious rooms. However, doors and closets could still limit your choices. When you increase the size of your bed and have two sleepers who want their side to enter and exit the bed, you’ll be more limited in smaller rooms and may only have one placement. 

Remember that you’ll also need to leave enough space around the bed for things like nightstands and dressers. It’s generally recommended to leave at least thirty inches of space on either side of the bed and at the foot of the bed. This way, you’ll have plenty of room to move around and won’t have to worry about bumping into furniture in the middle of the night.

Also, think about the design of your bedroom and how you want it to look and feel. Do you prefer an open, airy space or one that’s cozy and intimate? If you want your bedroom to feel more spacious, choosing a bed size to accommodate this is essential. For example, if you are replacing a king-sized bed and currently find your room cramped, you might consider switching to a queen-size mattress. On the other hand, if you have a large room and your current queen-size bed feels lost, you could upgrade to a king. 

elevated mattress in bedroom

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2) Who Will Be Using the Bed 

Are you shopping for a bed for yourself or for someone else? Is it for you and your partner? How long do you want this bed size to work for? Whoever it is, you want to ensure they will be comfortable and get the recommended sleep they need to wake up feeling rested and rejuvenated. 

If you’re buying a bed for a child, you’ll obviously need a smaller size than if you’re shopping for an adult. But you might still want to consider future-proofing your purchase by choosing a bed size that will accommodate your child as they grow. For example, if you’re buying a bed for a pre-teen, a twin-size mattress may be too small in a few years. In this case, you might want to consider a full-size bed instead. 

One of the most significant factors when considering bed size is the sleeper’s height, especially when the bed is to be shared. If one person is much taller, you will want to size up, so both people are comfortable. No one wants their feet hanging off the edge of the bed! Here are some general guidelines when considering height: 

  • Under 5'5" – You will be comfortable on a twin-size or full-size mattress. 
  • Between 5'5" and 5'11" – You’ll probably be most comfortable on a queen-size mattress if you have a partner. Still, a full-size mattress will also work if you are single or sleep alone. 
  • Over 6'0" – If you’re tall, you might feel cramped on a full- or even queen-size mattress if you share a bed. A king-size mattress will give you the extra space you need to stretch out. If you’re 6'6" or taller, we recommend looking into a California king mattress if you sleep with a partner or a full XL if you sleep alone.

Mattress Sizes and Bed Dimensions Explained

Understanding mattress sizes is essential to finding the right bed size for your needs. In this section, we’ll go over all the different classic mattress size options available so you can make an informed decision. Remember that these dimensions are for the mattress only and don’t account for extra width or length from a bed frame, headboard or footboard. Those additions can add several inches to your bed’s total length and width. 

twin sized mattress

Twin (39" W x 75" L)

A twin-size mattress measures 39 inches wide by 75 inches long and is the smallest standard-size mattress. They are typically used for kids — especially those who have outgrown a crib and have graduated to their first “big kid” bed — or in spaces where every inch counts. 

In addition, their size makes them a popular choice when siblings share a room. In these cases, you may find twin beds being used as bunk beds in smaller rooms or as two separate beds in medium to larger spaces. This size is also prevalent among shorter single sleepers who don’t have a lot of extra space in their bedroom for a larger bed and who find a twin mattress plenty spacious for their needs.

Best For: Children, shorter single sleepers, small rooms and rooms with multiple beds.

Room Size: The minimum room size recommendation for a single twin mattress is 7' x 10'. We recommend a larger room size of 10' x 12' if you add extra furniture, have two beds in the same room or want a play area.

Twin XL (39" W x 80" L) 

A twin XL mattress measures 39 inches wide by 80 inches long. This makes it the same width as a twin mattress but is 5 inches longer. As a result, it’s a good choice for taller kids or adults who need more length. This is especially true for students who live in dorm rooms or small apartments. This size is also a good option if you want to use a twin bed in a guest room but don’t want your guests to feel cramped. 

Best For: Dorm rooms, guest rooms, small apartments and taller kids or adults who need more length in their beds.

Room Size: Just like a regular twin, the recommendation for a twin XL mattress is a 7' x 10' room minimum. A 10' x 10' or larger room is advisable if you add extra furniture or still want two beds in the same room.

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full sized mattress

Full (54" W x 75" L) 

Full beds, also known as double beds, are a significant upgrade from a twin. This size is 15 inches wider than a twin but the same length. A full-size bed measures 54 inches wide by 75 inches long, making it ideal for adults who need more space than a twin bed can offer but don’t have enough room for a queen. Single-sleeper adults love a full bed, especially if they sleep with pets. 

Full beds are also great for guest rooms where a queen-size mattress won’t work due to space limitations. Couples can still get a good night’s sleep on a full-size mattress, but they may find themselves a little cozy if they’re taller. 

Best For: Guest rooms, small bedrooms and adult single sleepers.

Room Size: The minimum room size recommendation is 10' x 12' if you keep the room minimalist in furnishings with only nightstands. If you want to add extra furniture or have two beds in the room, a larger size like 12' x 12' or bigger is more suitable.

Full XL (54" W x 80" L)

A full XL mattress is the same width as a full mattress but 5 inches longer, making it ideal for taller single sleepers who need more length. Like twin XL and full mattresses, a full XL can be a good choice for a guest room since it offers more space but doesn’t take up as much room as a queen. Your guests will appreciate the extra length, especially if they’re taller than average. 

Best For: Guest rooms, small bedrooms and teenage or adult single sleepers who are taller than average. 

Room Size: The minimum room size recommendation is 10' x 12' if you’re keeping the room airy and not featuring many other furniture pieces. A 12' x 12' or larger size of room is best if you want to add additional pieces of furniture like nightstands, a dresser or a desk.

queen sized mattress

Queen (60" W x 80" L)

Queen beds are the most popular bed type and measure 60 inches wide by 80 inches long. This extra width and length make queen beds ideal for couples who want more space to themselves than what a full-size mattress can offer but can’t accommodate the width of a king-size mattress. 

They’re also suitable for taller adults, even if you sleep alone, as you’ll have plenty of room to move around and get comfortable. Those with small pets or kids who like to sleep in their parents’ bed may also find a queen-size mattress is just the right size. 

Best For: Couples, standard-size primary bedrooms, taller adults and those with small pets or younger kids who like to sleep in their parents’ bed.

Room Size: The minimum room size for a queen mattress is 10' x 12', but we recommend at least 12' x 12' so you have plenty of space to move around and can place a couple of nightstands in the room. If you plan on adding extra furniture or having other items like a treadmill or desk in the room, you should ensure the space measures 14' x 20' or more.

king sized mattress

King (76" W x 80" L)

King-size beds are the largest standard size available and measure 76 inches wide by 80 inches long. This extra width makes king-size beds ideal if you need maximum sleeping space or share your bed with kids or pets who like to sprawl out. 

King beds are also great for taller couples who need more length and room to move around. Just be aware that a king mattress will be cumbersome and require two people to move it. Make sure your doorways and staircases are wide enough to accommodate it. One great solution is a bed in a box, which can be easily delivered, moved, and set up in your bedroom.

Best For: Couples, families who co-sleep, larger bedrooms, those with pets and taller adults.

Room Size: The minimum room size for a king-size bed with nightstands is 12' x 12', but that will be a very cozy environment. We recommend going for at least 12' x 14' so you have space to maneuver around. If you don’t want your bed to dominate the room and plan on adding extra furniture like a dresser, armoire or a chair, a 14' x 20' room will give you more breathing room. A 16' x 24' room will provide you with even more space and allow for a bedroom that feels luxurious. 

California King – 72" W x 84" L 

The last size we’ll cover here is a California king, which measures 72 inches wide by 84 inches long. This mattress is slightly narrower and longer than a standard king-size bed and is an excellent option if you’re tall. It’s also a good choice if you want something wider than a queen but longer than a king. Sometimes, sheets might be a bit tough to find, as this size is less common. 

Best For: Tall adults, those who want maximum length and smaller spaces where a standard king wouldn’t fit.

Room Size: Follow all the same rules as a standard king when it comes to room size recommendations, except you’ll need a bit more clearance to accommodate the length of the mattress. 14' x 16' is the minimum room size we recommend, with 16' x 24' giving you plenty of extra space. 

king bed with soft green comforter

Final Word on Bed Sizes

Now that you know more about bed sizes, it’s time to decide. What size is right for you will depend on many factors, including your budget, the size of your bedroom and how much space you need to feel comfortable. 

Keep in mind what we’ve outlined here are some general recommendations and guidelines. We understand that everyone’s situation is different. Yes, a single person who loves to sleep with their dog might feel more comfortable on a king, while a couple who co-sleeps with their toddler could do just fine in a queen-sized bed. It’s about finding what works best for you and your sleeping habits.

After you’ve settled on the size, you’re ready to explore the many types of mattresses available to find the perfect one for you. From memory foam to latex to innerspring, there are plenty of options on the market. And don’t forget, you can always pair your mattress with a box spring, adjustable base or platform bed frame to get the perfect night’s sleep. 


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