What Size Bed Should You Get? Mattress Size Guide + Calculator

Key Takeaways

• Queen mattresses are the most popular size bed among adult couples.
• The best size bed for your space depends on the size of your bedroom, the furniture you have, and the fixtures you can’t block, like doors and vents.
• For the most comfortable fit, your bed size should accommodate the number of sleepers, your height, and your preferred sleep position.

If you want to sleep comfortably, choosing what size bed you should get is one of the first things to decide. Whether you want to know the best bed size for couples or you’re looking for the perfect size bed for yourself — your sleep needs, available space, and personal preferences will make a big difference in which mattress size is best for you.

Most adults under 6 feet will find queen size and larger beds comfortable, but the mattress size you ultimately choose may vary.

Not sure how to decide which size bed you should get? Use the bed size calculator below to get an estimate of the sizes that may be the best fit for your space and needs.

Bed Size Calculator: What Size Bed Do You Need?

If you’re wondering if a bed will fit in your room, the calculator below can help you determine the maximum bed size for your space. Before you can use our bed size calculator, you’ll need to know the following information:

• Bedroom dimensions in feet and inches
• Number of walls your bed will be against
• Number and type of bedroom furniture pieces
• Number of sleepers, including children and pets

By inputting this information in our calculator, you’ll get custom recommendations for the bed sizes that will fit best in your space while serving your needs.

How To Choose the Right Bed Size for You

If you want to know if a specific bed will fit in your room, or you’re not sure what your options are, you can figure out the best size bed for your needs by following the nine steps outlined below.

1. Measure Your Bedroom

Before buying a bed, you need to make sure that whatever size bed frame and mattress you choose will fit in your bedroom. Start by measuring the full length and width of the room. If your room is a non-standard shape, use your best judgment to decide whether you use the longest or shortest measurements for the closest approximation.

Once you determine your room dimensions, you should measure additional features and fixtures in your room, including:

• Doors: Measure the length of all doors, and if they open into the bedroom, account for how much space you need to open them fully. Leave at least one foot of space between the edge of the door and any other furniture.
• Furniture: From dressers and nightstands to benches and bookshelves, account for how much floor space your bedroom furniture needs.
• Windows: Most people prefer to keep their windows unblocked, but placing your bed against a window is not unheard of.
• Vents: Avoid blocking air vents that are on or near your baseboards.

You can sketch out your bedroom dimensions on paper to get a sense of how much space you have, or you can go by the measurements alone.

2. Determine Mattress Dimensions

Once you know how large your bedroom is, familiarize yourself with standard mattress sizes to determine the best fit. You can start by measuring the mattress you currently have to see how big your bed is.

Standard mattress sizes range from 38 to 76 inches wide and 75 to 84 inches long. The minimum bedroom size for a queen bed will be larger than a full or twin but smaller than the recommended room size for a king bed. 

Most primary bedrooms are at least 10-by-12 feet, but secondary bedrooms, guest rooms, dorm rooms, and smaller apartment bedrooms may not offer as much space.

3. Leave Some Extra Room

By the numbers, you could fit most mattresses in an average bedroom. But even if the surface area of a mattress is smaller than the size of your room, you may have trouble fitting it depending on the bedroom furniture you have, the layout of your home, and the size of your doorways.

For example, king and queen beds have the same length, but a queen bed will fit better in a narrower bedroom, leaving plenty of room for furniture and walking paths. An over-crowded bedroom can cause more stress than comfort, so even if you’d prefer a larger size bed, leave enough space for other fixtures.

4. Account for Your Height

What’s comfortable for each sleeper may vary, and individuals over 6 feet, 2 inches may have limited options that provide enough space. When choosing a bed size for your height, the rule of thumb is to add six additional inches to the height of the tallest person who will sleep in the bed to get your ideal length.

Those extra six inches provide enough space for pillows and blankets while ensuring each sleeper gets the support they need. For very tall sleepers or larger co-sleeping familiar, it may be worth considering larger bed sizes, though these are harder to find and can be costly.

5. Consider the Number of Sleepers

The number of adults, children, and pets sleeping in a bed can majorly impact the bed sizes you should consider. Whether you sleep with a partner or co-sleep with kids and pets, knowing how much space each person needs will inform your choice of bed size.

For larger co-sleeping families, standard bed sizes likely won’t offer enough space for everyone to sleep comfortably. Consider larger sizes like the Alaskan king or family beds to best accommodate co-sleeping arrangements.

6. Accommodate Your Sleep Position

Your sleep style may not seem as relevant to the size of your bed as other factors, but it’s important to consider. 

Combination sleepers — especially those who share a bed —  may need a larger bed than sleepers who don’t move around as much. Side sleepers, on the other hand, may be comfortable sleeping on smaller beds since they don’t take up as much space as stomach or back sleepers.

7. Choose Your Ideal Mattress Thickness

Mattress size and thickness are two different measurements, and different mattress sizes may be available in various thicknesses. Twin, twin XL, and full mattresses may have thinner constructions on average than larger beds that are designed to support more than one person.

Thicker mattresses may also be more appropriate for people who require additional support or weigh more. You should also check the mattress weight limit to ensure you will be comfortable regardless of the mattress thickness.

Generally, you can categorize mattress thicknesses into the following:

• Low profile: Less than 6”
• Slim: 6-9”
• Standard: 9-12”
• Deep: 12-14”
• Extra-deep: More than 14”

Thicker mattresses often have more interior layers, which can affect comfort and durability as well as mattress firmness. Be sure to choose a firmness level and thickness that best suits your needs.

8. Set Your Budget

A new mattress is an investment in your comfort and well-being, so set your budget accordingly. In most cases, larger bed sizes have a higher price tag than smaller beds. Depending on the materials, construction, brand, and quality, twin and full size mattresses typically cost less than a queen, king, or California king.

Keep in mind that purchasing a different size bed than what you currently have means you’ll need to buy other bed accessories such as a base and bedding. No matter what size bed you choose, finding a mattress that suits your space, keeps you comfortable, and fits your budget should be your top priority.

9. Plan Ahead

The size of your family and how long you plan to stay in your home can significantly impact the bed size that’s right for you. If you’re interested in co-sleeping arrangements, thinking about adopting a new pet, or planning to move soon, consider the timelines of these potential life changes before committing to a bed size.

Moving a mattress can be challenging, and replacing your bed just to accommodate extra sleepers can be an unnecessary expense. It’s often best to plan ahead and think carefully about the bed size that will best serve your needs.

Couples who want a king size bed but have different preferences can opt for a split king, or two twin XL mattresses, to accommodate their needs and make moving easier, as a twin XL is only 38-by-80 inches compared to the king’s 76-by-80 inches.

Why Your Mattress Size Matters

Deciding what size bed you should get matters because it directly affects your comfort and sleep quality, as well as your bedroom’s layout. With the right mattress size, you have more room to shift positions, regulate body temperature, and comfortably share your bed with a child or pet.

Before you go shopping for the right mattress size, remember that what works best for you may not be what other people prefer. It’s important to choose a mattress size that suits your space and serves your needs.

A Mattress For Everyone

We offer mattresses in all standard sizes to suit your unique needs, preferences, and space.

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