King Bed Frame Dimensions Guide (+ Sizing Chart)

Key Takeaways

• Standard king bed frame dimensions are 78-81 inches wide by 82-85 inches long.
• Bed frames add an extra 2 to 5 inches to each side of a mattress. The extra difference varies by manufacturer and bed frame style.
• King bed frames fit best in rooms that are at least 12-by-12 feet.

When picking the best mattress size for your room, it's important to consider the additional space that bed frames require. Not only will this ensure you have enough space in your home, but it will also help you figure out what kind of mattress to buy.

King mattresses are the second most common bed size falling just behind queen beds.¹ King size beds are great options for couples looking for extra space. So, just how wide is a king size bed?

King mattresses measure 76-by-80 inches, and king bed frame dimensions add 2 to 5 inches to the length and width of a king size mattress. 

Keep reading to understand all you need to know about king bed frames, including their dimensions, comparisons with other similar beds, and considerations for buying a king bed frame.

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What Are the Dimensions of a King Bed and Frame?

A standard king size bed frame typically measures 78-81 by 82-85 inches, which is approximately half an inch to 2 inches wider than a king size mattress. Keep in mind that bed frame sizes can vary from 2 to 5 inches depending on brand and bed frame style.

The base within a king bed frame must match how wide a king size bed is — 76 inches wide and 80 inches long. Be sure to take your bed frame’s dimensions into account when purchasing a new mattress or rearranging bedroom furniture. 

King vs. Other Bed and Frame Sizes

Let’s take a look at how a king size bed measures up to its closest counterparts. The table below includes a full list of mattress and bed frame sizes for the most popular bed sizes on the market. 

King vs. Full Bed Frame

King size mattresses are quite larger than full beds. In comparison to a king, full beds are nearly 2 feet narrower and 5 inches shorter. 

Full bed dimensions (width by length):

• Mattress: 54-by-75 inches
• Frame: 56-59 by 77-80 inches

Full size beds, also known as doubles, are typically purchased by adult single sleepers who may not have room for a queen size bed. They also work well for older children or toddlers transitioning out of a crib bed.

King vs. Queen Bed Frames

The difference between a king size bed and a queen size bed is a full 16 inches in width.

Queen bed dimensions (width by length):

• Mattress: 60-by-80 inches
• Frame: 62-66 by 82-86 inches

Though many people are perfectly happy to share a queen size bed, a king size bed can afford couples much more space to move around without having to worry about getting into their partner’s personal space. Thus, the king size bed is perfect for couples with different sleeping habits, such as light sleeper-heavy sleeper pairs and couples wherein one partner moves around a lot in their sleep. 

King vs. California King Bed Frames

The main differences between a standard king size bed and a California king are length and width. California king beds measure 4 inches narrower and 4 inches longer than standard kings. 

California king bed dimensions (width by length):

• Mattress: 72-by-84 inches
• Frame: 74-77 by 86-89 inches

Given the added length, California kings are best for taller couples who want enough space to fully stretch out in bed. 

King vs. Super King Bed Frames

Despite what its name may suggest, super king size beds are actually slightly smaller than standard kings by just a few inches. The king size bed measures 4 inches wider and 2 inches longer than the super king size bed.

Super king bed dimensions (width by length):

• Mattress: 72-by-78 inches
• Frame: 74-77 by 80-83 inches

Super kings are specialty beds that fit into bedrooms just shy of 12-by-12 feet. 

As a non-standard size, most super king bed frames are custom-built. Super king mattresses and bedding also are not as readily available in stores as accessories for the standard king and California kings. 

King vs. Split King Bed Frames

The difference between a king and a split king bed is that the split king comes with two twin XL size mattresses priced as one mattress. When connected, two twin XL mattresses make a split king and measure the same size as a king. 

Split king bed dimensions (width by length):

• Mattress: 76-by-80 inches
• Frame: 78-81 by 82-85 inches

The bed frames are also the same dimensions but a split king bed frame may have special features to keep the two mattresses together.

There are many benefits to owning a split king, including:

• Isolating motion transfer so that you don’t wake your partner up, even if you’re on different schedules or one partner tends to toss and turn at night
• Allowing couples with different firmness or support preferences to customize their sleeping experience without compromising the comfort of their partner
• Providing an extra mattress at home (this is only possible if you use two separate twin XL bed frames)

Who Should Buy a King Bed?

King size beds are most commonly purchased by couples, as most single sleepers do not need the extra space a king bed provides. With the widest space among all the standard bed sizes, a king size bed is an excellent choice for couples who:

• Want extra space
• Have a partner who’s a restless sleeper 
• Want an adjustable split king base
• Co-sleep with little kids and/or pets

Pros and Cons of a King Size Bed Frame

King size mattresses paired with supportive king bed frames offer several benefits and some potential drawbacks, but if a king size bed will help you sleep better, it’s likely worth it.

Here are a few pros and cons of the king size bed:

Considerations for Buying a King Bed Frame

When shopping for your next mattress, consider the following factors to help you choose the bed size and corresponding frame that’s best for your needs and preferences.

Number of Sleepers

King beds are typically purchased by couples for at least two adults to share, though a king can comfortably fit one or two small children or pets as well. 

Single sleepers typically do not need the space a king bed provides. But if you’re single and have the space and budget for a king bed, why not create a bedroom fit for royalty and upgrade to a king size bed?

Height

If you’re particularly tall or sleep with pets at the foot of your bed, you may find a king bed too short. Sleepers over 6 feet tall may begin to feel their toes reaching the end of the mattress or footboard, especially when sleeping with numerous pillows. Compared to a king or queen, a California king bed and frame offers an additional 4 inches of legroom and may be more comfortable.

You should also factor in your physical height with the bed’s height from the floor to the top of the mattress. Bed frames of all sizes come in various heights, including king bed frames, but if you’re tall, you’ll want to choose a bed frame height that’s comfortable to get in and out of.  

Sleeping Preferences

If you’re a restless or hot sleeper or sleep with a partner, you may want to opt for a bigger bed like a king. The closer you sleep next to a partner, the more likely you’ll feel their every move, so putting more distance between you may help you both sleep better. A split king may be even better for couples who:

• Follow different sleep schedules
• Sleep in different positions
• Prefer different mattress feels
• Have specific sleep disorders or concerns 

Split queen beds exist but are much harder to find.

Bedroom Size

When choosing a bed frame, you’ll need to ensure it fits in your bedroom. 

King beds fit best in bedrooms measuring at least 12-by-12 feet. If your room is not a perfect square but is at least 144 square feet, place the head of your bed on the shorter wall to maximize walking space.

It’s recommended to allow 2 to 3 feet of space around each side and the foot of a bed for furniture and room to walk. So although you could squeeze a king inside an 11-by-11-foot room, you would have very little room for any extra furniture.

Frame Materials and Design

Most bed frames are available in different designs and materials. Wood, upholstery, and metal are the most common materials used to build a bed frame. Each material plays into the aesthetic of the overall bed frame style.

The exact measurements of a bed frame vary by the type of bed frame and the brand that makes it, though typically bed frames add 2 to 5 inches to each side of a mattress.

Some of the most well-known bed frame styles include:

• Panel bed frames 
• Platform bed frames
• Adjustable bases
• Four-poster or canopy bed frames
• Wrought iron bed frames
• Floating bed frames 
• Bed frames with drawers or shelves for extra storage
• Bunk or loft beds
• Trundle beds
• Murphy beds
• Daybeds

Budget

Mattresses and bed frames vary in price based on their materials, size, quality, and brand. As the second largest standard bed size, king mattresses and bed frames are typically priced higher than those of a smaller size. For a high-quality product, expect to budget $2,000+ for both the cost of a mattress and bed frame. Lower priced options are available but may not last as long. 

Sleep Like Royalty on a King Size Bed

A king bed frame is a great investment for your bedroom, providing you with years of comfort and relaxation. But before you start shopping for a new bed frame or mattress, make sure to consider all the different dimensions and sizes available so you can get a bed suited exactly to your needs. 

If you’re looking for a king size bed and frame that can offer comfort, stability, and more, Purple mattresses pair perfectly with our different bed frames:

• Purple Bed Frame: A standard upholstered foundation with versatile grey fabric 
• Purple Metal Platform: A lightweight, minimalistic, and storage-friendly metal frame
• Purple Premium Smart Base: An adjustable, remote-controlled bed frame that lets sleepers adjust their sides of the bed separately
• Purple Premium Plus Smart Base: A step above the adjustable Purple Premium Smart Base with additional comfort features like underbed lighting, lumbar support, and vibrating massage

Whatever you’re looking for, there is a Purple bed frame for you!

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Designed with your comfort in mind, Purple king size mattresses provide the support and relief you need to rest easy.

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