Mattress Size Guide: Secrets for Every Room

Along with your bed’s firmness, support, and conforming qualities, the right size mattress can significantly improve your sleep. Many people choose a smaller mattress than what they need and end up feeling too uncomfortable to sleep.

With so many bed sizes available, how do you know which fits your sleep style best?

This article discusses different mattress sizes and dimensions (standard and non-standard) and the recommended size of your bedroom for each bed size. We will also explore how to choose the right mattress sizes and size bed dimensions.

Mattress Sizes and Bed Dimensions Guide

In the United States, the mattress’s width and length are traditionally measured in inches. Other countries have different sizes that are measured in centimeters.

If you’re interested in measuring your own mattress, lay a tape measure from top to bottom and across its middle.

Shop By Mattress Size

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Shop King

Shop Cal King

Crib: 28 inches by 52 inches

Room size requirements: 7 feet by 10 feet

The crib mattress only fits inside a crib and is regulated by the federal government for safety reasons.

This size mattress is usually medium firm and no thicker than 6 inches. To sleep comfortably on a crib mattress, a child must be shorter than 3 feet. If the child is taller than 3 feet, consider buying a small single mattress.

Small Single: 30 inches by 75 inches

Room size requirements: 7 feet by 10 feet

The small single mattress is excellent for toddler beds. The small single mattress is a standard mattress size, so most toddler bed frames will support it.

Twin: 38 inches by 75 inches

Room size requirements: 7 feet by 10 feet

The twin-size mattress is 38 inches x 75 inches—8 inches wider than a crib bed. The twin bed fits children, smaller teens and other single sleepers but isn’t long enough for a full-grown adult. An adult’s feet will hang over the edge, making it harder to get a good night’s sleep.

Twin mattresses are compatible with bunk bed dimensions and conserve space for those living in a small apartment or sharing a room.

Twin mattresses are easy to move because they are lightweight and small enough to maneuver in narrow hallways.

SEE ALSO: Best Mattress for Kids

Twin XL: 38 inches by 80 inches long

Room size requirements: 9.6 feet by 10.6 feet

The twin XL size mattress is 5 inches longer than the twin bed, making it best for taller people single sleepers.

The twin XL mattress is a popular mattress size for college dorm rooms and pairs well with bunk beds and other single sleepers. Twin XL mattresses aren’t as expensive as full or queen size beds, so keeping one handy a mattress for a guest room is an affordable alternative.

Full: 54 inches by 75 inches

Room size requirements: 9.6 feet by 10.6 feet

A full size mattress, or double bed, doesn’t provide enough space for a couple but is a notable upgrade for a single sleeper. A double bed offers enough space to spread out but doesn’t take up much floor space, making it a good option for teenagers or young adults.

Double mattresses aren’t as expensive as queen mattresses, but they are a bit harder to move because they aren’t as compact and lightweight as a twin XL.

Full XL: 54 inches by 80 inches

Room size requirements: 9.6 feet by 10.6 feet

A full XL mattress has an extra 5 inches of legroom, better suiting the height of a full-grown adult. It’s essentially a queen with a few inches shaved off the sides.

We don’t suggest this size for couples because the width is too narrow. However, this bed makes an excellent guest room bed.

Queen: 60 inches by 80 inches

Room size requirements: 10 feet by 10 feet

Queen mattresses are the most popular size because they fit in most bedrooms. We suggest this mattress size to couples who don’t need much space or a single adult who needs extra room.

The queen size bed is an excellent option for a guest or master bedroom. Many people get queen mattresses for their older teenagers and turn it into a guest bed when the child moves out.

Queen size beds come as split queens (two separate mattresses). These work well for couples with different firmness preferences.

Olympic Queen: 66 inches by 80 inches

Room size requirements: 10 feet by 10 feet

The Olympic queen offers 6 additional inches of width for couples who want just a little bit extra room. This mattress isn’t part of the usual size run, so it can be tricky to find along with matching bedding.

You can use Olympic queen size mattresses in RVs, campers, and mobile homes.

King: 76 inches by 80 inches

Room size requirements: 12 feet by 12 feet

King mattresses measure 16 inches wider than queen beds, so it provides enough room for two people to have their own space. It’s lengthy enough to accommodate adults of average height, though some over six feet tall may find themselves a little cramped.

There is also the split king mattress, which is two twin XL beds side-by-side. This option lets couples choose different firmnesses without compromising on a single mattress. Many people choose this size because it works well with adjustable beds.

California King: 72 inches by 84 inches

Room size requirements: 12 feet by 12 feet

California king mattresses are 4 inches narrower and 4 inches longer than a king mattress. The extra length can accommodate extra tall people. The California king size mattress can comfortably fit two adult sleepers and parents who co-sleep with a child.

The California king bed comes in a split option, so each sleeper can select a different mattress firmness from their partner.

How to Choose a Size

You want a bed big enough to encourage restful sleep, so you will need to consider who sleeps in the bed, how much space they need, and your bedroom’s size.

Who Sleeps In the Bed?

If you’re buying for yourself, you most likely know what mattress size suits you best; however, if you have a sleeping partner or children you co-sleep with, you have to think about their sleep preferences as well.

Mattresses for a couple depend on the two sharing a bed:

• Full beds don’t offer enough room for a couple to sleep comfortably.
• Sleeping partners who like to cuddle may enjoy a queen mattress.
• If you and your partner need space, a king or California king provides it.

Meanwhile, single sleeper who enjoys sprawling would fit comfortably on a full. Those who don’t mind a more compact mattress can also enjoy a twin XL mattress

Refer to our guide below to find the best mattress size for your circumstances.

Toddlers, children, or young teenagers are comfortable on these mattress sizes:

• Small Single
• Twin
• Twin XL
• Full

Single adults, college student, or older teenagers are comfortable on these mattress sizes:

• Twin XL
• Full
• Queen

Two adult sleepers are comfortable on these mattress sizes:

• Queen
• King
• California King

Two adult sleepers who co-sleep with children or pets are comfortable on these mattress sizes:

• King
• California king

Your Body Type

Your height may affect the bed size you need to sleep comfortably. For people 5 feet 5 inches or taller, we suggest a mattress at least 80″ long to prevent the feet from dangling over the bed’s edge and disrupting sleep.

Room Size

Before you buy a bed, consider the surface area of the bedroom the mattress will occupy. A larger mattress needs more surface area space than a small bed. You need to leave enough surface area room for movement between the mattress, the walls, and any furniture.

Overcrowding the bedroom surface area can make your sleep environment stressful, which can make it hard to fall asleep. Sometimes you can cheat a little, such as with a Murphy bed mattress that’s put away during the day. Still, make sure to measure your room before deciding on a mattress size.

Here’s a refresher on room size requirements for mattress sizes:

Your Sleep Position

Your preferred sleep position can give you an idea of how large a sleep surface you need. If you toss and turn a lot or sleep spread-eagle, you’ll need more room than someone who uses a small portion of the bed.

Those who need more legroom and restless sleepers should choose a larger mattress; on the other hand, couples who like to snuggle or those who don’t take much space can sleep comfortably on a smaller bed.

Consider Your Home

Mattresses are heavy and can get damaged when you’re moving them from place to place. If you plan on buying a large bed, such as a king size mattress or California king size mattress, you might want to wait until you’re settled in your forever home—or a place you are going to live in for at least 10 years.

Consider how you’re going to move your mattress. If you’re purchasing a larger mattress, your home might not allow it. Measure doorways and halls so ensure you’ll have enough room to maneuver it.

You might consider getting a mattress in a box, which is shipped to your doorstep in a small box—this way, you can easily move the mattress to your bedroom.

Budget

Larger mattresses contain more materials and, therefore, cost more. If you want a bigger bed, you will need a larger budget. Twin mattresses commonly cost between $300 and $600, and a quality queen size mattress can cost between $700 and $2000.

You’ll have to consider the material quality and type of mattress you want to buy, too:

• Buying a cheap mattress may seem like a good way to save money initially, but you’ll have to replace it more frequently than higher-quality beds, costing you more money in the long run.
• Some mattress types, like all-latex and hybrid mattresses, cost more than others.

Your budget may not only include a new mattress but other items you need to buy, like an adjustable bed.

Non-Standard Mattress Sizes

If you’re interested in larger or smaller mattresses outside of the usual range, such as oversized family beds or camper mattresses, you may want to look into customizable mattresses. Some mattress manufacturers will take special orders for certain size bed dimensions, along with a shopper’s choice of mattress materials.

This is one way to find a mattress that works with an antique bed or that fits into an RV or boat’s sleeping space. Costs can vary when it comes to custom mattresses, but many are quite affordable.

A custom-order mattress is one way to get your hands on the biggest possible bed sizes, such as the Texas king, Wyoming king, and Alaskan king. These oversized beds need large bedrooms, but they can easily fit multiple sleepers.

SEE ALSO: Best Texas King Mattresses

Comparison Guides

If you find yourself debating two similar sizes, such as full and queen or king and California king size bed dimensions (Cal king), it can help to compare their pros and cons in depth. We have written a number of mattress comparison guides to make this easier:

• Twin vs. Twin XL: What’s the Difference?
• Twin vs. Single: What’s the Difference? 
• Twin vs. Full: What’s the Difference?
• Full vs. Queen Mattress: What’s the Difference?
• King vs. Queen: What’s the Difference?
• King vs. California King: What’s the Difference?
• King vs. Split King: What’s the Difference?
• Twin XL vs. Split King: What’s the Difference?

We also have written a number of size guides for different frames and special types of mattresses:

• Futon Mattress Sizes and Dimensions
• RV Mattress Sizes and Dimensions Guide
• Bunk Bed Mattress Sizes Guide
• Murphy Bed Sizes and Dimensions Guide
• Mattress Foundation Sizes and Dimensions Guide
• Bed Frame Sizes and Dimensions Guide
• IKEA Bed Sizes and Dimensions Guide

Frequently Asked Questions

What’s the difference between a twin and single mattress?

Despite the different names, single and twin size mattresses are the same size, both being 38 inches wide x 75 inches long. The name difference started because twin beds were originally sold in a pair, thus the term “twin.” Eventually, brands started selling twin mattresses separately and started calling them “single” mattresses.

The term “single” stuck around for a while, but brands started calling single beds “twins” once again, despite there only being one bed of the same size. Nowadays, calling a 38 x 75 inch mattress a “single” is more common in Europe and the UK, while the term “twin” is commonly used in the US and Canada.

Can I use a mattress topper to make a smaller mattress for two more comfortable?

While a mattress topper can provide extra cushioning and support, it may not be the best solution for making a smaller mattress comfortable for two people. Mattress toppers are designed to enhance the comfort of a mattress, but they cannot increase the actual size of the sleeping surface.

If a mattress is too small for two people to sleep comfortably, it’s best to consider upgrading to a larger size, such as a queen or king, to ensure both individuals have enough space to rest well.

Does size affect how often I need to replace my mattress?

Generally, mattresses should be replaced every 7-10 years, depending on factors such as usage, quality, and individual comfort preferences. Mattress size does not directly impact the replacement timeline, as all sizes should be replaced within this general timeframe.

However, larger mattresses, such as kings and California kings, may show signs of wear more quickly if they are used by heavier individuals or if the weight is not evenly distributed. It’s crucial to assess your mattress regularly for signs of wear, sagging, or discomfort. Replace it when necessary to ensure you sleep well at night.

How do I know if my room is large enough for a king size bed?

Consider the bed’s dimensions and how you will set it up in your room. To comfortably fit a king-size bed, there should be sufficient space on either side of the bed for nightstands and room for people to walk around.

If you plan on having other furniture, such as dressers or chairs, think about where you’ll place them so the room doesn’t feel too cramped.

Are there any benefits to choosing a non-standard mattress size?

While these sizes can offer some benefits in specific situations, such as accommodating unique room layouts or individual preferences, there are several drawbacks to consider. Firstly, these mattresses are often more expensive due to their custom nature and limited availability. This can make them a less attractive option for budget-conscious shoppers.

Moreover, finding accessories like bed frames, box springs, and bedding for non-standard sizes can be challenging and more costly. Furthermore, if you decide to change your bed frame or move to a new home in the future, a non-standard mattress size may not travel or fit as easily, potentially requiring you to purchase a new mattress altogether.

Are there any drawbacks to choosing a larger mattress size?

Yes, these mattresses are more expensive than smaller sizes due to the increased materials needed for their construction. Additionally, larger mattresses require more space in the bedroom, which may not be suitable for smaller rooms or apartments.

Moving and transporting these mattresses can also be more challenging due to their size and weight, which can be problematic if you relocate frequently or need to navigate narrow hallways or staircases.

How do I determine the right mattress size for my child’s room?

Think about your child’s age, growth potential, and the available space in the bedroom. For younger children transitioning from a crib, a twin-size mattress is often suitable and can accommodate them for several years.

However, if your child is taller or you want a mattress that will last through their teenage years, a twin XL or full-size mattress may be more appropriate. Measure the room and ensure that there is enough space for the mattress and other furniture while allowing for easy movement around the bed.

How do I dispose of my old mattress when upgrading to a new size?

When purchasing a new mattress, many retailers offer removal and disposal services for your old mattress as part of their delivery process. This is often the most convenient option, as the retailer will take care of the heavy lifting and ensure that your old mattress is disposed of properly.

Alternatively, if you prefer to handle it yourself, you can donate your old mattress if it is still in good condition and meets the organization’s donation guidelines. If your mattress is not suitable for donation, check with your local waste management company for recycling and junk pickup options, as some areas require special handling or pickup arrangements for large items like mattresses.

Do I need to visit a store to determine the right size?

No, you don’t need to leave your home to pick out the right mattress size. Instead, you can measure out a rough space and imagine how the mattress would accommodate you. Many online mattress retailers offer detailed size guides, room planners, and customer support to help you buy the right mattress without trying it out in person.

Trustworthy retailers also offer risk-free trial periods, allowing you to test the mattress in your home for a specified number of nights before committing to your purchase. This trial period ensures that you have chosen the right size and comfort level for your needs.

Can I order a custom-sized mattress?

Yes, if you have a unique bed frame or require a specific mattress size, you can reach out to mattress manufacturers or specialty bedding stores to inquire about custom sizing options. Be sure to measure your bed frame carefully, including the interior dimensions and any unique features, such as built-in headboards or footboards, to ensure a proper fit.

Keep in mind that custom mattresses may come with a higher price tag and longer lead times compared to standard sizes.

Conclusion

Whether you sleep alone, with a partner, or co-sleep with children or pets, there is a mattress size that can accommodate your needs. It’s essential to consider not only your personal preferences but also the size of your bedroom and your budget when making a decision.

While it may be tempting to opt for a smaller mattress to save space or money, doing so can lead to discomfort and poor sleep quality. On the other hand, selecting a mattress that is too large for your room can create a cramped and cluttered environment, which can also negatively impact your sleep.

Taking the time to research and compare different mattress sizes and types can help you make an informed decision that will provide you with the comfort and support you need for years to come. Don’t hesitate to reach out to mattress experts or take advantage of online resources and trial periods to ensure that you find the perfect mattress size for your unique situation.