Mattress Guides

King vs. California King Size Mattress

By Liam Hinton, August 24, 2022

King and California king mattresses are the two largest standard mattress sizes you can buy. Large beds are great for couples, single sleepers who want to stretch out, and people with big bedrooms.

Lots of people assume California king mattresses are larger than king mattresses, but this isn’t correct. California king mattresses are longer than king mattresses, though they’re also narrower and have an overall smaller surface area.

We summarize the differences between the two popular mattresses along with important considerations to determine whether a king versus California king size mattress is best for you.

Mattress SizeKingCalifornia King
Width76 inches72 inches
Length80 inches84 inches
Total Surface Area6080 square inches6048 square inches

What is a King Mattress?

A king mattress, also called an Eastern king, is 76 inches wide and 80 inches long. It’s the largest standard size mattress, with an overall surface area of 6080 square inches. Standard king size mattresses are the same size as two twin XL mattresses pushed together, also known as a split king mattress.

The standard king size bed is great for couples looking for more sleeping space. If you’re a parent, you could even fit in bed with a partner and two children.

With Eastern king beds, you do need a large master bedroom. Your room should be at least 12 by 10 feet, though a 13 by 13 foot room may feel more balanced.

Pros of King Mattresses

  • Good option for couples with children
  • Ideal for wide master bedrooms
  • Readily available
  • Available in split king form for couples with different firmness needs


  • Expensive
  • Too large for some bedrooms
  • Heavy and difficult to transport

What is a California King Mattress?

A California king mattress, also known as a Cal king or Western king, measures 72 by 84 inches and has a surface area of 6048 inches. California kings are the longest standard size mattress available.

People often mistakenly assume California king beds are the largest mattress size, especially since bed sizes are listed from smallest to biggest on mattress sites and California kings are listed after regular kings. However, based on the surface area, California kings are just a bit smaller than your standard king.

The extra length of California king beds makes them suitable for two tall adults over 6 feet tall. Since Cal kings are more narrow than kings, you can still sleep two adults with one or two children, though it may be a bit of a squeeze.

Cal king size beds fit in large master bedrooms at least 12 by 12 feet, though a bedroom size of at least 12 by 14 feet is best to accommodate the length.

Pros of Cal King Mattresses

  • Works well for tall people
  • Suitable for long and narrow rooms
  • Fits narrow master bedrooms
  • Good for couples who like to sleep close together


  • Expensive
  • Heavy
  • Less personal space for couples

Do You Need a King or California King Size Mattress?

When deciding between a king or California king, consider the following: your room size, the approximate costs, your height, and whether or not you share a bed.

Room Dimensions

In your bedroom, there should ideally be at least 2 feet of space around the three sides of the bed and bed frame, minus the side against the wall, so there’s enough space to walk around and add other furniture.

California king beds should be in a room at least 12 feet wide and 12-14 feet long. For wider bedrooms (at least 12-13 by 10-13 feet) an Eastern king mattress is better.

If the size of your bedroom is too small for either bed, your next option is a queen size mattress, the most common bed sizes available.


Due to their size and the number of materials needed to construct them, both king and California king beds are the most expensive mattresses on the market. You can expect to spend between $750 to over $3000 on a king or California king mattress, depending on the quality of materials and any added technologies in it.

Your Height

When deciding between the two mattress sizes, consider your height. If you’re over 6 feet tall, the additional length of a California king bed prevents your feet from hanging over the bed. However, if you’re under 6 feet tall, you likely won’t need the foot room, so a king bed is ideal.

Your Sleeping Partner

For couples choosing between Cal kings and standard king mattresses, consider your sleeping positions and how much personal space you both need.

For couples who want to stretch out, a regular king mattress is the best option because of its extra width. However, couples who don’t mind sleeping close together should consider a Cal king bed. Still, if you and your partner are each less than 6 feet tall and have bedroom space, you might simply choose the standard king over a California king regardless to save money on the mattress and accessories.

When you and your partner have different firmness preferences, you may choose a king because they’re available in split king form, meaning you both can choose your firmness. Split king beds are also compatible with split adjustable bases, so you and your partner can adjust your inclines to fit your personal preferences.


Do California king sheets fit a king mattress?

Cal king sheets and king sheets aren’t interchangeable. Cal king sheets are too narrow and long for a king mattress, so while they would fit the length of a king mattress with extra fabric, they would have to stretch quite a bit to fit a king mattress’s width. King size sheets, on the other hand, are too short and wide for a California king mattress, so they wouldn’t cover the entirety of the mattress.

What’s the size difference between a king and queen mattress?

King and queen mattresses are the two most popular mattress sizes for adults. Queen mattresses measure 60 by 80 inches and have a surface area of 4800 square inches, a whole 1280 square inches fewer than a king mattress.

Although queen mattresses are much smaller than king mattresses, queen beds fit in nearly all master bedrooms while king beds require more space. Queen beds are also a suitable option for both single sleepers and couples.

Do two twins equal a king?

No, two twins pushed together aren’t equal to any standard mattress size. Two twins together are as wide as a king mattress, both being 76 inches, but aren’t as long, with the two twins only measuring 75 inches. Instead, they make a square-shaped bed unsuitable for standard bedding. However, two twin XL mattresses pushed together equal a king and function as a split king.

Why is it called a California king?

California king mattresses are named after the place they were invented. In the late 1940s, a Los Angeles merchant realized California had large enough homes and lifestyles to accommodate large beds. So, he designed a 6 by 7 foot bed, the California king.

What is an Alaskan king mattress?

Alaskan king mattresses are easily one of the largest mattresses ever, measuring 108 by 108 inches (9 by 9 feet). These square beds are very rare since they’re unnecessarily huge. Unless you’re planning to fit five or six people in one bed, California king and king mattresses are sufficiently large and easy to find.

Is a King or California King Mattress Better For You?

The main difference between king and California king mattresses is their length and width. While the differences are minimal, we recommend a king mattress for couples who want lots of personal space, people with wide bedrooms, co-sleeping families, and budget-conscious shoppers. On the other hand, we recommend a California king mattress for taller people, people with narrow bedrooms, and couples who don’t mind sleeping close together.

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