When it comes to picking out a bed size, many people focus more on their height and the number of sleepers using the bed. While these are vital factors, you can’t forget your room size. No matter how big a bed you think you need, it won’t do you any good if you get it home only to find it’s too big or too small.

The thing is, just because a bed can fit in a room doesn’t mean it’s a good fit for the room. Some bed sizes leave larger rooms looking empty. Some bed sizes are so big they might not leave enough room for other furniture.

Generally speaking, you need about two feet of space around three sides of your bed to get enough clearance to walk around in your room. However, you’ll need more space than that if you want additional bedroom furniture. You’ll also need to consider how big a bed to get if you have a large master. Let’s take a look at which mattress sizes fit best in which rooms.

Mattress Size

Twin Bed Dimensions

The twin mattress is a good size for people with the smallest rooms. The twin size bed is 38 by 75 inches, meaning it can fit in a room as small as 7 by 8 feet. Most newer houses don’t have bedrooms this small, but many older homes do. You may also want to convert a smaller room like a walk-in closet or maid’s room into a bedroom. Twin size mattresses are perfect for this.

Keep in mind, if you want a chest of drawers or other bedroom furniture, you’ll need a larger room. Seven by 10 feet is considered the minimum recommended room size for a traditionally furnished bedroom with a twin mattress. If you want a multi-twin room, you’ll need to up the size of your room width to 12 by 10 feet.

Twin XL Bed Dimensions

Taller sleepers who need a compact space will appreciate the twin XL mattress. The twin XL size bed is 38 inches wide, but it adds 5 inches of length to bring this twin variant’s total length to 80 inches.

You can still have a 7-foot wide bedroom with a twin XL, but because this bed is longer than a twin, you’ll need a minimum room length of 9 feet. Again, you’ll need to account for bedroom furniture. This may necessitate a room of 10 or even 12 feet in length.

Full Bed Dimensions

Full size beds are an ideal choice for single active sleepers. These 54 by 75-inch mattresses are perfect for single adults who need a little extra width to toss and turn. Full mattresses are still a bit too narrow for couples, though. They offer less space per person than a baby crib or toddler bed.

When it comes to room size, full or double beds are exactly 4.5 feet wide, so you’ll need to increase your room width to at least 9 feet. Since fulls are only 75 inches long, you can still have a 10-foot long room and whatever bedroom furniture you want.

Queen Bed Dimensions

Couples who have smaller master bedrooms or don’t want to break the bank might consider the queen size bed. At 60 by 80 inches, queen size mattresses offer each partner about 30 inches of surface area apiece. Queen beds are also a good choice for tall active sleepers who find a full size bed too short.

The queen mattress can fit into rooms as small as 10 by 10 feet and still leave space for dressers, nightstands, etc. This makes them an excellent choice for guest rooms, minor master bedrooms, and children’s rooms alike.

King Bed Dimensions

Standard or eastern king mattresses are a good choice for couples who can’t cut it with the narrower queen bed size. The king size bed gives couples 38 inches of space apiece, so it’s just like sleeping in a twin XL bed.

At 76 by 80, king size mattresses need a larger bedroom to avoid a cramped look. To fit all your furniture and have space to walk around the bed, you’ll need a room of about 12 by 12 feet. If your master bedroom is larger than 12 by 12, one of the king bed variants may be the only option you have to avoid an empty-looking room.

California King Bed Dimensions

The tallest of the tall sleepers might enjoy the California king. At 72 by 84 inches, the California king mattress is long and narrow, just like the state for which it’s named. This bed is just about the only standard mattress size that can accommodate sleepers well over 6 feet tall.

California kings need longer and narrower rooms. You can get away with putting a Cal king in a 12 by 12 room just like a standard king, but if you want a more proportional look, you may need a 12 by 14-foot bedroom.

Split King Bed Dimensions

Split kings are the same measurements as regular kings. They just feature two twin XL mattresses in the same king size bed frame instead of a single king size mattress. There are tons of advantages to this setup. But one of the best ones is it allows couples with different personal preferences to have distinct materials, firmness levels, and adjustable base settings.

The good thing about split kings, too, is that they require the exact same room dimensions as a regular king. If you’ve already got a standard king in a room that fits it, you can swap it out for a split king.

Non-Standard Mattress Sizes

The above mattresses are known as the standard bed sizes. They’re the ones you’ll find at pretty much any bed store or website. On the flip side, there are several other non-standard sizes you can special order or find online.

Small Twin

The small twin or small single bed is 30 by 75 inches and can work for single sleepers with the smallest of small spaces, like college students or young adults with studio apartments.

Full XL

If you like the full size bed’s width but need some extra length, the full XL may work for you. The full XL bed has the width of a full size bed, but it’s 80 inches long. That’s perfect for taller sleepers who don’t have enough space for a queen.

Olympic Queen

The 66 by 80-inch Olympic queen could be the perfect size for couples who want a bit more width than that offered by a standard queen but don’t have the room for a king.

California Queen

The 60 by 84 inch California queen bed could be the best choice for couples or taller individuals who need the length of a Cal king but don’t have the space for its additional inches of width.

Wyoming King

The Wyoming king makes it hip to be square. This bed measures 84 inches on all sides and is perfect for larger rooms that even a king or California king bed can’t fill out.

Texas King

Everything is bigger in Texas, including its namesake king bed. At 80 by 98 inches, the Texas king offers over 54 square feet (7840 square inches) of sleeping space.

Alaska King

For those who want to go big or go home, the Alaska king is a great choice. At 108 by 108 inches (or 9 by 9 feet), this whopping mattress is big enough that a room of the same dimensions could fit a twin bed.


What bed size should I get if I have a huge master bedroom?

That depends on the size of your bedroom. If your master is 12 by 12 or 12 by 14 feet, you could go with a California king or a regular king. However, if you’ve got an even bigger room you need to fill out, you might consider one of the oversize king beds.

Wyoming kings will still fit in a 12 by 12-foot room for those who just want a giant bed. However, Texas kings need a room of no less than 12 by 14 feet, and Alaska kings can’t fit in a room of less than 16 by 16 feet.

Which is the best bed size for couples?

That depends on the couple. Most couples find that a queen bed works just fine for them. However, there are some scenarios in which couples might need to upgrade. Couples who like to spread out or toss and turn all night might find a queen bed isn’t wide enough. Parents with small children who like to share a bed might also find a queen isn’t large enough. These couples may need a king.

Extremely tall sleepers may also find a California king is long enough to offer sufficient legroom and wide enough to sleep two people. Couples with larger master bedrooms may also need a king or Cal king.

How tall should my ceiling be for bunk beds?

There’s no universal ceiling height for bunk beds because not every set is the same height. However, you can determine how much height you need by subtracting the height of your potential new bunk bed set from the height of your ceiling. You need 33 to 36 inches of space between the top of the mattress and the ceiling to avoid head bumps and other accidents.

Are there other factors that determine what bed size I need?

In addition to your room size, there are several other factors that can influence your needs. Your height is an important factor in your mattress size choices. Those under six feet tall can have any mattress, but those over six feet tall may not be able to sleep on a mattress less than 80 inches long.

The number of sleepers sharing the bed is another vital consideration. Couples need at least a queen. Parents who co-sleep with their children can benefit from a king. Larger families who co-sleep with several small kids might even need an oversize king.

What is the best bed size for a guest room?

Typically, guest rooms are smaller than masters. That means king beds are probably too large for most guestrooms. However, if you have couples or taller sleepers coming over, twin or full beds may not cut it.

Queen beds are typically the most versatile of all the mattress sizes. They are small enough to fit in most modern bedrooms. They’re also big enough to accommodate most couples and most individual sleepers.

Bottom Line

The size of your bedroom is a huge factor when determining the size of your new mattress. Whether you get a teeny tiny twin or a supermassive Alaska king, your bed is only as big as the room you put it in. Take measurements before shopping, and you can rest assured you’re buying the right size before you bring home your new bed.