So, you’ve decided to invest in better sleep. Congratulations! Buying a new mattress can effectively help you address some common challenges that interfere with a good night’s rest.

For example: the right mattress can:

• Help you manage chronic pain for quality sleep
• Align your neck and spine and promote the best sleeping position for maximum comfort
• Better support your body and reduce pressure points if your weight is heavier
• When adjustable, a mattress can ease joint and muscle stiffness, reduce snoring, and help you more easily get into and out of bed

“Good health depends on good sleep, and good sleep depends on a good mattress,” said Dorothea Vafiadis, Senior Director of NCOA’s Center for Healthy Aging. “If you’re tossing and turning at night, a new mattress might be exactly what you need to wake up refreshed and energized."

When you’re ready to shop, we’re ready to assist. As you poke around the mattress store testing out your preferred firmness, you’ll also want to think about dimensions. Maybe you already have. Close to 80% of people surveyed by the Better Sleep Council said they knew what size mattress they wanted before they shopped for one.¹

Still, it’s worth taking a pause. Most mattresses last an average of 8–10 years; some make it to 15 or more.²

“That means it could be a long time before you need to buy one again,” Vafiadis pointed out. “Why not consider up front whether a little extra length or width could improve your sleep comfort and quality well into the future?”

Our comprehensive guide to standard and non-standard mattress sizes can help you sort through the options: from small singles to Alaskan kings and everything in between.

Overview of mattress sizes: a chart

Before we dive in, this chart quickly gives you a sense of what’s out there.

Mattress sizes and bed dimensions

*Rounded to the nearest inch

^†Rounded to the nearest foot

You may wonder why your height—or the height of anyone else who will sleep on the mattress—matters. It’s for two reasons:

• To ensure proper support around your entire body
• To allow room for extra pillows

“If your mattress is too short, your feet may hang off the bed, or you may find yourself cramped on the edge, which prevents your muscles from fully relaxing,”  Vafiadis said. “That’s why mattress companies suggest a mattress that’s at least six inches longer than the tallest person sleeping on it.” Having enough space also allows you to use pillows to prop up your torso or support your back, hips or knees, a simple technique that can promote restorative sleep, she explained.

Room size matters, too—especially for accessibility. If you or someone else in your home uses a wheelchair, it’s important to leave at least 36 inches (three feet) of clear space around your bed, according to the Americans With Disabilities Act (ADA) standards. (In the chart above, we’ve left four feet).

Now, let’s cover each individual mattress size in more detail.

Standard mattress sizes

You’re probably pretty familiar with the seven standard choices by their names already—which include twin; twin XL; full; full XL; queen; king; and California king.

While every rule has an exception, standard mattresses generally are less expensive than non-standard ones. That’s because they’re mass-produced; economies of scale mean that materials, manufacturing processes, and even transportation costs are cheaper.

That said, prices (and quality) still can vary widely. Before you buy, it’s a good idea to consider whether a standard mattress is the best choice for you, your space, and your lifestyle—or if a custom size is worth the potential extra cost.

Twin (single) mattresses

Many of us slept on a twin mattress growing up. It remains a typical children’s size today; twin mattresses also can work well for smaller-framed adults whose bedrooms don’t have space for bulky furniture.

Twin mattresses in detail

Twin XL (extra-long) mattresses

At 80 inches, a twin XL mattress is the same length as both a standard queen and a standard king. This can make a world of difference for taller people who don’t want or can’t fit a wider mattress than a twin into their space.

Twin XL mattresses in detail

Full (double) mattresses

Despite being called a “double,” you may find it challenging to fit two adults onto this size mattress. That’s because it’s only 15 inches wider than a twin. Full mattresses are best for people who typically sleep alone and have space for a bigger bed.

Full mattresses in detail

Queen mattresses

Nearly half of people in the U.S. who bought a mattress in 2019 chose a queen.¹ This size works well for a variety of people, room sizes, and sleeping positions—including single sleepers who take up more space and couples who prefer proximity.

Queen mattresses in detail

King mattresses

Measuring 16” wider than a queen, a king-size mattress is the same size as two twin XLs pushed together. It’s well suited for roomy bedrooms and co-sleepers who enjoy the same personal space they would have on their own twin mattress.

King mattresses in detail

California king mattresses

At 72” wide, a California king straddles the line between a queen and a traditional king. At 84” long, it offers even more leg room for people who are extra tall. It’s a good compromise for people who want more space than a queen provides without the full bulk of a king.

TABLE 7: California king mattresses in detail

Non-standard mattress sizes

Many manufacturers offer a variety of mattress sizes that fall outside the typical standard measurements. While this increases your choices, it also means you may end up spending more: if not for the mattress itself, then for a bed frame or bedding that will fit it. You’ll want to keep this in mind when shopping.

You can find non-standard variations of twin, full, and queen-size mattresses. Mattresses larger than a California king size are considered oversized.

Small single mattress

A small single mattress is the same length as a standard twin but 8 inches narrower.

Small single mattresses in detail

Full XL (extra-long) mattress

This mattress size is the same width as a standard full but 5 inches longer.

Full XL mattresses in detail

Olympic queen mattress

An Olympic queen is the same length as a standard queen but 6 inches wider.

Olympic queen mattresses in detail

RV mattress sizes

These mattresses are designed to fit into recreational vehicles (campers). They’re a little trickier to define because there’s no manufacturing standard for them. Still, RV mattresses are necessarily smaller than their standard counterparts. The most commonly found sizes are shown below.

Oversized mattress options

Oversized mattresses are significantly larger than king and California king mattresses. Because they measure at least 7 feet at their longest side, you need a lot of space to accommodate them. Across the board, these mattresses are best for single sleepers who are taller and larger-framed than average, as well as couples and co-sleeping families.

The image below can help you determine whether an oversized mattress makes sense for your personal needs and available space.

Texas king

A Texas king is 18 inches wider and 4 inches longer than a standard king.

Texas king mattresses in detail

Wyoming king

A Wyoming king is 4 inches wider and 8 inches longer than a standard king.

Wyoming king mattresses in detail

Vermont king (Alberta king)

A Vermont king is 16 inches longer and 20 inches wider than a standard king.

Vermont (Alberta) king mattresses in detail

Alaskan king

An Alaskan king is 28 inches longer and 32 inches wider than a standard king.

Alaskan king mattresses in detail

Family

This mattress is truly designed for a combination of adults, kids, and pets.

Family mattresses in detail

Family XL

A family XL mattress offers 4 inches of extra width and 2 feet of extra length.

TABLE 16: Family XL mattresses in detail

How to choose the right mattress size

With so many options available, it’s easy to feel overwhelmed. But there are several objective facts to consider that can help narrow things down. These include:

How tall you are

When it comes to mattress size, your height matters more than your weight. (If you have a heavier frame, take a look at our guide to mattress firmness and the best mattresses for heavy people for more info.) You should be able to lie down comfortably without any part of you dangling off the top or bottom edge of the mattress.

If you’re between 5’4” and 5’9” (the average height range for adults in the U.S.),³ you will fit on any mattress. That’s because the shortest two—twin and full—are both 75” long. Choosing either one offers at least 3” of extra length to enjoy.

On the other hand, if you’re any taller than 5’9”, you’ll want a longer mattress. Here are some general guidelines:

If you’re between 5’9” and 5’11”, consider a:

• Twin XL
• Full XL
• Queen
• King
• California king

If you're between 6'0" and 6'6", consider a:

• California king
• Wyoming king

If you’re 6’6” or over, consider a:

• Wyoming king
• Texas king
• Vermont king
• Alaska king
• 
  

If you co-sleep with another adult, consider a:

• King
• California king
• Wyoming king
• Texas king
• Vermont king
• Alaska king

How big your bedroom is

You might really want a king-size mattress. But if it takes up most of the floor space in your room, it’s probably impractical—and might be unsafe. You (and your sleeping partner if you have one) should easily be able to move around the bed. If you use a walker or wheelchair, this means having at least three feet (36”) of open space on three of the four sides, according to official ADA guidelines.

“Even if you don’t use mobility aids, having  extra space around your bed reduces the risk of bumping into walls and tripping over furniture, common causes of trips and falls that can potentially lead to serious injury, ” NCOA’s Vafiadis said.

To account for other bedroom furniture and storage, we recommend allowing four feet (48”) of open space around three sides of each mattress. (To calculate this easily in the store, simply add four feet to the mattress length and eight feet to its width).

Here's a quick reference:

If your bedroom is 11’ x 11’ or less and you sleep alone, consider a:

• Twin
• Twin XL

If your bedroom is between 10’ x 12’ and 11’ x 13’ and you sleep with a partner, consider a:

• Full (double)
• Queen

If you’re furnishing a camper (RV) and want maximum comfort, consider a:

• RV queen
• RV king

Whether you have strength or movement concerns

Do you have limited upper body or core strength? Do you often change positions while you sleep?

According to Anne Davenport, PT, DPT, you may have difficulty getting to the edge of a larger mattress if your mobility is limited. On the other hand, a smaller mattress may not suit if you roll around a lot at night. This is especially true if you worry about falling out of bed.

“When you’re shopping for a mattress, think about both your comfort and your safety, ,” Vafiadis advised. “And while none of us knows what the future holds, it’s worth asking yourself what size mattress is practical for me now—and will still feel practical a few years from now?”

For example, you might anticipate that today’s mild arthritis might progress over time. Choosing a mattress now that also will work well for you later can be a sound financial decision.

Think about the following scenarios:

If you can’t easily maneuver into and out of bed, consider a:

• Twin
• Twin XL

If you often change positions and/or worry about falling out of bed, consider a:

• Queen
• Olympic queen
• King
• (Remember to keep your room dimensions and mobility in mind; you may need to choose the smallest of these larger sizes to ensure easy, safe movement in and around your bed).

If you have certain health conditions

Some medical disorders cause you to move around a lot at night—perhaps without you even knowing it. Others improve when you deliberately shift your sleeping position.

For example, people with REM sleep behavior disorder physically “act out” their dreams and can make sudden, violent movements with their arms and legs.⁴ While rare, this condition typically affects adults age 50 and over.⁵

Restless legs syndrome (RLS) is more common, especially as we age.⁶ People with RLS experience itchy, achy, or throbbing legs paired with an intense urge to move them around. This disrupts quality sleep.

Obstructive sleep apnea and acid reflux (indigestion) can, too. People who live with these conditions often find relief by sleeping in a more upright position.

Do you have one of these conditions? A larger mattress can be more comfortable and help you sleep better. Take the following into account.

If you have a condition that leads to deliberate or inadvertent movement, consider a:

• Full (or larger)

If you often want or need to prop yourself up with extra pillows, consider a:

• Full XL (or larger)

If you sleep with a partner and one or both of you lives with one of these conditions, consider a:

• Split king adjustable bed with two twin XL mattresses

If you share your bed

Will more than one person be sleeping on your new mattress? If so, you’ll want to take everyone’s height, preferred sleeping positions, and health conditions into account. In situations where one partner snores, moves around a lot, or frequently gets up at night, a larger mattress can help minimize disruptions and lead to a better night’s sleep.

These guidelines can help.

If you and your partner like to cuddle up, consider a:

• Queen

If you and your partner need more personal space, consider a:

• King

If one or both of you are taller than 6’2” or prefer extra leg room, consider a:

• California king (or larger)

If two of you share your bed with pets, consider a:

• King (or larger)

If your family co-sleeps and includes three or more people and pets, consider a:

• Family
• Family XL

What position you sleep in

Are you most comfortable curled up on your side? Or do you love to “starfish” into every corner and edge of the bed?

What about pressure points? Do you sleep with a wedge between your knees to reduce soreness and align your spine?

No matter how much—or little—space you take up on your mattress, it’s important to think about roominess. Having an extra buffer allows you to use multiple pillows, for instance, and even can help you better regulate your body temperature. Plus, even if you usually sleep on your side, you likely roll over once or twice overnight. A slightly larger mattress might mean you don’t have to limit your movement when you do.

Keep these scenarios in mind:

If you sleep in your own bed and like extra space, consider a:

• Full (or larger)

If you sleep in your own bed and use extra pillows, consider a:

• Full

If you sleep with a partner and one or both of you uses extra pillows, consider a:

• King

If you sleep with a partner and one or both of you runs hot, consider a:

• King

How much you want to spend

Last but certainly not least, it’s important to pay attention to your budget.

Many of the best available mattresses range in price from $937–$3,049 for a standard queen size. Larger mattresses cost more than smaller ones, as do non-standard sizes compared to standard ones.

Still, a lot depends on the brand, materials, and any extra features you choose. Often, you can save money by waiting for seasonal sales; taking advantage of manufacturer incentives; using discounts you might qualify for; and buying a floor model. 

Frequently asked questions

Does mattress size affect sleep quality?

It certainly can. The ideal dimensions for you depend on things like your height, the size of your bedroom, whether you share your bed with other people or pets, if you have mobility or medical concerns, and even which position(s) you best like to sleep in. Because most mattresses last an average of 8–10 years, it makes sense to consider all of these factors carefully before you buy—and to choose the mattress size that best meets them.  

What are the standard mattress sizes?

There are seven of them: twin, twin XL (extra-long), full (double), full XL, queen, king, and California king. Standard sizes tend to cost a little less than non-standard or custom sizes due to economies of scale in materials, manufacturing processes, and transportation. That said, only you can define the relationship between price and value when it comes to your sleep. Investing a little extra up front may yield invaluable health rewards well into the future.

What's the best bed for three people?

Many families choose to co-sleep. And the industry has responded with mattress sizes that can accommodate more than two people. When shopping, think about all of the same things covered above: the height of each sleeper, their preferred sleeping position, any health or mobility considerations, and the size of your bedroom. Depending on the number of pillows (standard size is 26”), start by considering a king mattress and move up from there.

Twin vs. full mattress: What’s the difference?

Full mattresses often are called “doubles”, but this is a bit of a misnomer. Compared to twin (single) mattresses, full-size ones offer 15” in extra width. That’s enough to fit a second standard pillow—but two adults likely would feel pretty squeezed. On the other hand, if you typically sleep alone, enjoy a little extra room to stretch out, and have the space for it, a full mattress could improve your sleep comfort and quality.

Queen vs. king mattress: Which should I choose?

A standard king mattress is 16 inches wider than a standard queen. (Their length is the same). If you’re 6’2” tall or less—and the size of your bedroom isn’t a concern—then you might consider whether the extra lateral room could improve your sleep. Will other people or pets share the same bed? Do you (or they) move around a lot? Would you like space for extra pillows? You’re the best judge of value for the price.