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The Ultimate Mattress Size Chart and Bed Dimensions Guide

Last Updated on November 28, 2023

Written by Jill Zwarensteyn

The different sizes of beds seem easy enough to understand, right? The truth is, choosing the right size for your mattress can be more complicated than you may think. Does it fit comfortably in my bedroom? Is there enough leg room? The list goes on.

To help you make a decision when selecting the best mattress for you, we’ve put together a summary of the most common measurements you will see online and in a store so you can have an idea if it’s a perfect bed for you and your bedroom.

Common Bed Size Dimensions Comparison

TypeSize (Inches)Suitable For
Small Single or Cot 30 x 75Babies and toddlers
Twin38 x 75Kids that have outgrown their cribs and single adults living in smaller apartments. It’s also great for a daybed or bunk bed.
Twin XL38 x 80Kids, taller adults, and those who want to use an adjustable bed frame
Full54 x 75Good for a single sleeper, someone with children or pets, and couples that do not require a lot of leg room.
Full XL54 x 80More than enough for a single sleeper. Also good for couples that need more leg room but can not accommodate queen size due to bedroom limitations.
Queen60 x 80Frequent choice and a perfect size for most couples that do not need a lot of sleeping space. If you plan to sleep alone this is more than enough.
Olympic Queen66 x 80Six Inches wider than a standard queen, it makes it nice for someone who doesn’t want to upgrade all the way to a King.
King76 x 80Great choice for couples who want maximum personal sleeping space. Check our room dimensions scale guide to ensure it will fit in your bedroom.
California King72 x 844 inches longer but 4 inches narrower than a standard king type. Good for taller individuals.

Small Single Bed (Cot) Dimensions

Illustrated image of Small Single Cot Dimensions

This is the size of crib mattresses. They can also serve as toddler beds in most cases once your baby outgrows the cot. Typical measurements are 30” wide and 75” long.

If this is what you’re looking for, check out our Best Crib Mattresses here.

Twin Bed Dimensions

Illustrated image of Twin size bed dimensions in inches

A typical single, twin, or bunk mattress is 38” wide x 75” long. You’d be hard-pressed to find a bed that is any smaller than this one, other than a toddler bed or crib.

Typically, a twin mattress is ideal for children who have outgrown cribs and toddler beds, and who are now ready to graduate to a larger mattress.

Additionally, it works well for those who sleep in tight quarters, have small rooms, or share a room with a sibling or roommate, Twin beds are an ideal choice. Twin beds are often used as day beds, bunk beds, dorm room beds, and in guest rooms.

Twin XL

Twin XL Bed Dimensions Illustration

There are subcategories of double beds to consider as well. The Twin XL is typically 80” L while still maintaining the 38” W. If you’re an adult looking for a bed that saves space and still is a comfortable choice, a Twin XL mattress may be perfect for you.

Find Out More: Twin XL vs. Twin

Can I use a Twin XL mattress on a King Size Bed Frame?

Yes, you can use two double/twin XL beds in a king frame. If you are in a relationship where one partner requires a different firmness than the other, two separate mattresses could be a helpful solution.

Explore the best Twin XL beds.

Full Bed Dimensions

Illustration of full size bed dimensions in inches

Full-size mattresses measure 54” wide x 75” long, and these are also commonly referred to as “Standard Double.” The Full size is sufficient for adults that need more room than what a Twin can offer.

If you are in a relationship, this may not be the best choice for you, as the fit will be more snug. However, some couples that need to save money may prefer the price tag of a Full bed compared to the King and Queen models. Additionally, if you have a pet or child that sleeps next to you, you may want to consider a wider option.

We suggest the Helix Kids for a great Full size mattress. The Helix Kids is specifically designed for children, and getting a Full size in this bed allows the parent to lie next to the child in the event of nightmares or difficulty sleeping. We also suggest the WinkBeds Original for a great Full size mattress. Some couples may opt for a Full size mattress, and the WinkBed’s versatility for multiple sleep positions combined with solid edge support is ideal for partners.

Full (Double) XL

Double Bed XL measures in inches

A Full XL option is 54” x 80” giving you an extra 6 inches of leg space. If you do not require extra width but want some more room for your legs, this is a perfect option.

Want to read more? Check out our Double vs. Full mattress comparison.

Queen Bed Dimensions

Image showing a queen size bed dimensions in inches

Queen size mattresses are 60” wide x 80” long. They are typically long and wide enough to suit most sleepers. For those who sleep with their spouse, child, or pet, a Queen bed might be perfect. Check out some Queen Mattress Options here.

When looking at these larger sizes, it becomes necessary to consider the living space. Queen sizes and higher take up more room than the Twin or the Full, and your ability to freely move around the bedroom may become restricted.

If you have a larger bedroom, then this won’t be a factor.

We suggest the DreamCloud Original for a great Queen size mattress. Most shoppers who get a Queen bed are adults, and the DreamCloud offers a luxurious design that includes a cashmere blend cover, pillowtop surface, gel memory foam, and pocketed coils. We also suggest the Nectar Original for a great Queen size mattress. The Nectar excels at categories like pressure relief, support, and motion isolation for more comfortable rest.

Looking for more info? View our in-depth Queen vs. Full bed comparison.

Olympic Queen

Image showing the size of a Olympic Queen type

Olympic Queen mattresses are slightly wider and measure 66” wide x 80” long. An Olympic Queen is perfect for those who don’t want to upgrade all the way to a King but could use more width.

King Bed Dimensions

King Bed Dimensions Illustration

A standard King size mattress is** 76” wide and 80” long**. We recommend avoiding this size unless your room is at least 12×12 square feet. This is a perfect mattress for couples who sleep with their kids or pets and want more room for themselves.

If you want to compare this to other options, a King is the same as 2 Twin XL beds.

We suggest the Saatva Classic for a great King size bed. The Saatva’s construction includes premium support thanks to the dual coil unit, so those sharing a bed or who carry more weight shouldn’t experience much sagging. We also suggest the Nolah Evolution for a great King size mattress. The Evolution is equipped with multiple advanced cooling features, so couples are less likely to overheat during the night.

Looking for more details? Read our full King vs. Queen bed comparison.

California King Bed Dimensions

Illustrated image of California King measurements

The California King mattress is** 72” wide x 84” long** making it one of the biggest options on the market. This size is perfect for active sleepers, tall people, and couples with kids or pets. A California King is 4” longer but 4” narrower when compared to a standard King.

We recommend you have a large room of at least 12×12 square feet for a California King mattress.

View Our Full Comparison: California King vs. King mattress size

What to Have in Mind When Choosing the Right Mattress Size

Bedroom Size

You have decided that you need a new bed, but can you actually put it in your room and still be able to open the door and walk around it?

Let’s take a look at the following illustrations showing how certain mattress sizes will fit in your room.


When trying to find the right mattress size to fit the needs of you or your family, these are a few things to keep in mind.

First, if you’re planning on upgrading, make sure you know the dimensions of your current bed. You wouldn’t want to shop for a larger option and accidentally choose the same type.
Second, if you’re moving, don’t forget to measure the room that you’ll be sleeping in. It is awful to have a mattress that is too big for space. You’ll have issues getting around the room, and your space won’t be as aesthetically pleasing.

Third, who will be sleeping in it? If it’s just you, you are good to go with a Double. However, if you have a spouse, kids, or pets, you might want to opt for a larger option such as Queen. King is the ultimate comfort size if your room can accommodate it.

Now that you know more about the sizes you can check out our other guides on different mattress styles and brands.

Jill Zwarensteyn

Jill Zwarensteyn


About Author

Jill Zwarensteyn is the Editor for Sleep Advisor and a Certified Sleep Science Coach. She is enthusiastic about providing helpful and engaging information on all things sleep and wellness.

Combination Sleeper