The standard mattress sizes in the United States include Twin, Twin XL, Full, Queen, King, and California King, each with distinct dimensions and ideal use cases.

A Twin mattress measures 38 inches wide by 75 inches long, making it suitable for children, single sleepers, or guest rooms. A Twin XL extends the length to 80 inches, providing additional space for taller individuals or college dorms.

The Full mattress, also known as a Double, is 54 inches wide and 75 inches long, offering more room than a Twin and fitting well in smaller rooms or for growing children. A Full XL variant increases the length to 80 inches, accommodating taller sleepers.

The Queen mattress is the most popular size, measuring 60 inches wide by 80 inches long, and is ideal for couples who do not have children or pets sharing the bed, or for individuals who prefer extra space. It fits best in bedrooms with a minimum size of 10 feet by 10 feet.

The King mattress is 76 inches wide and 80 inches long, providing ample space for couples, families, or those who share their bed with pets. It requires a room of at least 12 feet by 12 feet to accommodate comfortably.

The California King is slightly narrower at 72 inches wide but longer at 84 inches, making it ideal for taller individuals or couples who need extra length. It also requires a room of at least 12 feet by 12 feet.

Additional specialty sizes exist, such as Split Queen (30 inches wide by 80 inches long) and Split California King (36 inches wide by 84 inches long), designed for adjustable bed frames where each side moves independently. Other specialty sizes include RV-specific options like Short Queen (60 inches by 75 inches), RV King (72 inches by 80 inches), and various waterbed and truck sleeper cab sizes.

Room size recommendations vary by mattress type, with a general guideline of 24–30 inches of walking space on each side and at the foot of the bed. The surface area of a Queen mattress is approximately 33.3 square feet, while a King is about 42.2 square feet, and a California King is 42.0 square feet.

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BedInABox
bedinabox.com › pages › mattress-size-guide
Mattress Size Guide | BedInABox
Learn which mattress size is the right fit for you! From twin to California King, choose from six standard mattress in a box sizes with our mattress size guide.
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Tampa Mattress
tampamattress.com › mattress-size-chart
Mattress Size Chart | Tampa Mattress Makers
October 16, 2025 - Dimensions: 38″ x 75″ Best for: Children, single sleepers, bunk beds Room size: At least 7′ x 10′ ... An XL twin mattress gives extra length for growing teens or tall adults.
Discussions

Guide to mattress sizes
Alaskan king could fit five people. Or one person and a dog. More on reddit.com
🌐 r/coolguides
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34173
November 18, 2022
A guide to mattress dimensions and bed sizes

Ah yes, the Alaskan king size for when you wanna have adult sleepovers.

More on reddit.com
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September 11, 2018
What size bed do you have?
I don't think you should downsize. Queen size is the perfect size for a single (adult) person. If you do bring someone home in the future a queen would be best. I'm single and I have a queen size mattress/ bed. If I had a huge room, I'd get a California King Size because I like to hog the entire bed, and I'd purchase one even if I was single.Don't compromise on your sleep. More on reddit.com
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March 7, 2021
mattress size
Why does stomach sleeper look like he was murdered and placed like that? More on reddit.com
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August 8, 2021
People also ask

What are the less common mattress sizes?

Three-quarter, Olympic Queen, and waterbeds fall into this category.

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tampamattress.com
tampamattress.com › mattress-size-chart
Mattress Size Chart | Tampa Mattress Makers
What’s the most popular mattress size?

Queen, since some bedrooms cannot accommodate a king size.

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tampamattress.com
tampamattress.com › mattress-size-chart
Mattress Size Chart | Tampa Mattress Makers
Can I use a mattress topper to make my mattress feel bigger?

Only in comfort, not in actual dimensions.

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tampamattress.com
tampamattress.com › mattress-size-chart
Mattress Size Chart | Tampa Mattress Makers
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Mattress Firm
mattressfirm.com › mattress-sizes-dimensions.html
Mattress Sizes And Dimensions: A Bed Sizing Guide
Once-A-Year Sale & Clearance is here: Shop our best deals online & in-store. Shop Sale · Join today & enjoy an extra 15% off online or in-store · Loading footer · Bed Sizes & Mattress Dimensions - Sizing Guide | Mattress Firm
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Zinus
zinus.com › blogs › zinus › what-mattress-size-do-you-need
A Guide to Mattress Sizes and How to Choose One for You | Zinus
March 17, 2020 - Shop smarter with our mattress sizes chart. From twin to king, learn about mattress sizes, full size mattress dimensions, and find your perfect fit.
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Big Fig Mattress
bigfigmattress.com › blog › what-size-mattress-do-i-need
Mattress Sizes Comparison: What Size Mattress Do I Need?
October 27, 2025 - First, strip all of the blankets, sheets, and pillows off of your mattress. Gather a retractable measuring tape and a pen and paper so that you can easily record your measurements. Measure the width and length of the bed, and record the numbers. Then, use the infographic below to decide what size mattress you have.
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Beautyrest
beautyrest.com › blogs › guides › mattress-bed-sizes-dimensions-comparison
Mattress/Bed Size Dimensions Guide 2023 | Beautyrest.Com
When comparing mattress sizes, remember we are talking about the dimensions in regards to width and length and not thickness because bed sizes are pretty universal +/- an inch. The height or thickness as some call it of a mattress will vary depending on the make and model of the mattress.
Find elsewhere
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Nest Bedding®
nestbedding.com › pages › mattress-size-guide
Mattress Size Guide
Mattress Sizes & DimensionsThe Guide to Find the Perfect Mattress Size Mattress Dimensions (inches) Twin: 38" x 75" Twin XL: 38" x 80" Full: 54" x 75" Queen: 60" x 80" King: 76" x 80" California King: 72" x 84" Split King 1-side: 38" x 80" Split ...
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Sleep Number
sleepnumber.com › home › resources
Mattress Size Chart and Bed Dimensions | Sleep Number
Reference Sleep Number's mattress size chart to explore mattress sizes and bed dimensions. You’re one step closer to choosing the right mattress for you.
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Helix Sleep
helixsleep.com › pages › mattress-sizes-explained
Mattress Sizes & Dimensions Explained in Detail | Helix Sleep - Helix Sleep
Because of its expanded dimensions at 60 inches wide and 80 inches long, a Queen bed size is often considered an upgrade from a Full size bed. A Queen size mattress is ideal for couples and individuals looking for extra space in the bed if a Full size mattress isn't quite roomy enough.
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DreamCloud
dreamcloudsleep.com › p › mattress-size-dimensions-guide
Mattress & Bed Size-Dimension Comparison Guide 2026 | DreamCloud
Refer to our mattress sizes guide & dimensions chart to compare the most popular bed sizes and mattress dimensions.
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Amerisleep
amerisleep.com › blog › mattress guides › mattress sizes chart (2026 guide) – dimensions in inches & cm
Mattress Sizes Chart and Bed Dimensions Guide (2026) - Amerisleep
Quick answer:A Queen mattress (60″×80″) is the most popular choice for couples in average bedrooms. Kings (76″×80″) offer maximum space for couples or families, while Full (54″×75″) suits solo sleepers in smaller rooms.
Published   November 13, 2025
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Tuft and Needle
tuftandneedle.com › blogs › guides › mattress-size
What Mattress Size is Best? A Bed Sizes Chart & Guide
May 15, 2025 - Your current sleeping arrangement and living space could be the reason you buy a twin XL over a full size bed, while future plans may lead you to purchase a king over a queen sized bed. When it comes to mattresses—one size does not fit all, but we’re here to share all the information you need to make sure you make the decision that’s right for you.
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Wikipedia
en.wikipedia.org › wiki › Bed_size
Bed size - Wikipedia
2 days ago - Equal to the width of two single mattresses. Super king: 200 cm (79 in) wide. Available in XL length only. Europe may traditionally have had more variations in national bed size standards than any other part of the world, but in the recent years a few sizes have become more common than others.
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Purple
purple.com › mattress-sizes-dimensions
Mattress Sizes Chart & Bed Dimensions Guide - Purple
Ease pain and sleep better with a Purple Mattress engineered for pressure relief and all-night comfort. Free delivery, easy returns, 100-night trial.
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Nectar Sleep
nectarsleep.com › p › mattress-size-dimensions-guide
Mattress Size Dimensions Guide | Nectar Sleep
Find the best mattress size for your space with our comprehensive guide. Compare bed dimensions to choose the best fit for your space. Start now!
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Leesa
leesa.com › pages › size-guide
Mattress Sizes: Dimensions & Measures for Perfect Fit | Leesa Sleep
Shop Leesa Twin Mattresses · A twin XL size mattress is 5 inches longer than a twin, making it perfect for growing children or adults with a small space. A twin XL is the standard mattress size for most colleges. Plus, two twin XL mattresses together make a king.
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Sleep Foundation
sleepfoundation.org › home › mattress sizes 101: finding your perfect fit
Mattress Sizes 101: Finding Your Perfect Fit
July 11, 2025 - Three of our testing team’s favorite mattresses are listed below. ... The sizes queen, king, and California king are all large enough to comfortably sleep multiple people.
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Better Sleep Council
bettersleep.org › mattress-sizes
Mattress Sizes - Better Sleep Council | Start every day with a good night’s sleep
February 27, 2024 - Sometimes still called a double mattress, a full-size mattress is 53 inches wide, which is just 15 inches wider than a twin size (or “single”). For a couple sharing a bed, that leaves each partner only 27 inches of personal space — or ...
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Reddit
reddit.com › r/coolguides › guide to mattress sizes
r/coolguides on Reddit: Guide to mattress sizes
November 18, 2022 - The mattress itself is only 4" taller than the average door opening, so if you feed it through at an angle and flex it a bit, it should squeeze through. Though that's with the measurements provided. It looks like most of the alaskan kings you can buy are 9'x 9', and I don't know how you get that through a doorway. ... Yeah. I've never seen an Alaska king sized as 12'x7'.
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Serta
serta.com › blogs › mattress-guides › king-size-mattress-dimensions
King Size VS California King Size Mattress Dimensions
A Serta king measures around 76″ x 79.5″. These measurements can vary by +/- 1/2″. Size availability varies by product and retailer. A cal king measures around 72” x 83.5”. Mattress heights vary by product, so please see your local ...