Bed Sizes and Dimensions Guide

By Alex Konrad | December 28, 2021

The mattress and bed frame industry is ripe with gimmicks and clever sales tricks that can lure even the savviest of buyers into purchasing something they don’t want or need. Our advice? Know before you go. 

Know what sizes and options are available before you hit the sales floor (or begin online shopping). This can save you time, money, and headache and help you find the perfect bed frame and mattress to suit your needs. 

We’ll cover how beds are measured, what sizes are available, and help you make a plan to purchase the perfect bed for your space. 

How Are Bed Sizes Measured?

Bed sizes are always measured by the mattress size. While the frame of the bed that includes the headboard and footboard can measure significantly longer than the actual size of the mattress, the standard measurements for mattresses will remain the same. 

As such, it is important to look at the dimensions of the bed frame, headboard, and footboard you select so you can be certain it will accommodate your space. 

Different Mattress Sizes

Mattresses are available in four standard sizes and three extended sizes. If you decide to use a non-standard (extended) size, you’ll need to make sure the bed frame, headboard, and footboard can accommodate the mattress you select. 


The twin bed is the smallest bed size available and is best for a single sleeper, usually a toddler or young child, although it can accommodate a single adult under 6’ in height comfortably. These beds are an affordable option for single sleepers and for children’s rooms or guest rooms.

Accessories and frames for these mattresses are widely available at most stores and online retailers and don’t need to be custom fitted. 

The measurements of the twin mattress are 39”x75”.

Twin XL

A non-standard sized mattress, the twin XL measures 39”x80”, giving the sleeper an additional five inches of length. This is ideal for a teenager or single adult sleeper and is the best option for a single sleeper guest room as it can accommodate an adult over 6’ tall. 

This also offers a single sleeper the option of sleeping with a pet or extra cushions and pillows if desired. The drawback of using a twin XL is that you’ll likely have to special order the linens. 


This standard-sized mattress is the first in our list that is wide enough to accommodate two sleepers, although depending on preference, it could feel like a very tight fit. 

The full mattress and bed measure in at 54”x75”, providing enough room for two adults, although it’s more comfortable for a single adult and possibly a furry friend. If you are planning a guest room that will only be used infrequently, a full-sized bed is a perfect option. 

The problem most people will find with a full is that the cost of the mattress and the frame is strikingly similar to the cost of a queen size mattress and frame but has much less surface and sleeping space. 

Full XL

A Full XL is another non-standard size that essentially adds just a bit more in terms of length. Just like the twin XL, the full XL offers the same amount of width but five additional inches of length, which can offer additional legroom for taller sleepers. 

Measuring 54”x80”, this is the least popular mattress size available, likely because the queen mattress is larger and extremely close in size to the full XL. For the amount of money spent on an XL full, a queen is truly a more cost-effective option. 


The queen is the most popular mattress size, measuring in at 60”x80”. This mattress comfortably accommodates two adults and is an effective option for practically any budget. The queen lends itself to fitting perfectly in practically any bedroom space. 

The queen bed can still feel cramped, depending on preference, and if the bed is shared with animals or children. If so, the king may be a better option. 

Accessories and bedding for the queen bed are widely available. 


The standard king bed is the essence of sleeping luxury. It also represents the largest jump in size between mattress sizes. Measuring 76”x80”, the king offers an additional 16 inches of width for the same amount of length. 

This bed is an excellent option for couples sharing a bed with a child or a couple who simply prefers maximum space. This bed generally has a much higher price point than a queen bed, and the sheer size of the frame can overwhelm a standard-sized bedroom. 

California King

For the ultimate in luxury, there’s nothing quite like the California king bed. Offering an additional four inches in length but slightly less in terms of width, the California king accommodates extremely tall individuals, couples who sleep with animals at their feet, or anyone who simply loves the feeling of sleeping unencumbered. 

This mattress size requires a specific frame, and oftentimes the bedding, frame, and mattress must be custom ordered. The average person or couple will have no need for a California king; however, it’s a consideration when shopping for mattresses.

How to Shop for a Bed by Size

While shopping for an actual bed is definitely more stimulating than shopping for the accompanying mattress, it can still be painfully tedious and difficult, especially if you aren’t quite sure what you need or the style you like. 

In terms of bedroom design, most of us would like a room that lends itself to peace, tranquility, and elegant serenity. Here’s how to create the perfect landscape for dreaming by incorporating the use of a beautiful bed. 

Determine What You need

Determining what you need is more than just selecting a mattress size. Consider the size options, of course, but also consider your space. If you long for a king bed but are working with a bedroom that will be overpowered by a king (or possibly not even allow it), you should look for a smaller size. 

Generally speaking, you will want a bed that allows for two feet of space around the sides that do not touch a wall. Consider, too, that that space shouldn’t be encumbered by another piece of furniture. In other words, if you have a dresser directly across from the foot of your bed, there should be a distance of at least two feet between the two items. 

Select a Simplistic Design

Minimalist isn’t boring; it’s understated and timeless. Modern furniture can withstand the test of time if you select pieces that are structured, seamless in design, and provide clean lines that can change and evolve with your space. 

Look for wood finishes, galvanized steel and copper, leather head and footboards, and neutral colors that easily accommodate changes in bedding and decorative style. 

Learn the Brand

Often overlooked but of maximum importance is making yourself familiar with the brand from which you will buy your bed. Online retailers and big-box stores have made it easy to simply point and click to purchase virtually anything you need; however, the quality and design style you expect may not show up on your doorstep. 

Items to consider when shopping from a brand include:

Consider the Availability of Accessories

A full XL may seem like a great idea for your teenage son’s bedroom, but if you plan to use that bed after he’s gone, consider the availability of other accessories and bedding. Will you need to custom order another bedding set to transfer the bed to another room or repurpose it as a guest room? Will the bed size you’ve selected be enough to keep future siblings comfortable if they will use the bed next? 

Helpful Hints

If you’re wondering when it’s time to replace your mattress, you should start shopping after you’ve had yours for seven years if it is used daily. If not, you can extend the life by three more years, but after that time, the materials in the mattress begin to break down and fail, leaving you with a mattress that is much less comfortable. 

Your bed frame should last significantly longer, especially if you buy a high-end piece of furniture crafted with care from materials that are designed to last. 

Don’t hide under the covers when it’s time to shop for a new bed. Use our guide to help you hone in on your needs and trust the team at Modloft to help you discover the most beautiful and restful mattresses and bed frame designs. 



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