Mattress Guides

California King vs. Eastern King vs. Regular King

One frustratingly common misconception that I run into at least once a week is how people understand the size difference between a California King and a regular (or Eastern) King mattress...Basically, they don’t.  Let’s break it down.

By Jack Mitcham

People tend to think the Cal King is a larger mattress. It’s not.

Overall, the California King mattress has a smaller surface area than a regular King mattress. The California King is 4 inches longer, but 4 inches narrower than a regular or “Eastern” King. (See where we do the math below.) That means a King mattress has more overall surface area and will offer more space between you and your partner than a California King does.

One overall rule of thumb when mattress shopping and deciding between the two sizes: If you’re on the tall side, like taller than 6-feet-2, get the Cal King. It has the length you need. If you’re sleeping with another normal height human being and just need more space, the Eastern King is your choice. It has the surface area you want.

Disclosure: By clicking on the product links in this article, Mattress Nerd may receive a commission fee at no cost to you, the reader. Read full disclosure statement.

Pros of a King Mattress

A regular King mattress is the “standard” version of the size, so the reasons to get a regular King sized mattress instead of California King will apply to more people. King is the big mattress for most people. For example:

  • The King has more overall space. A standard King (76″ x 80″) covers 6,080 square inches. A California King (72″ x 84″) covers 6048 square inches.
  • It’s easier to find sheets and other accessories for King mattresses. You’ll have a lot more choices and an easier time getting them. (This is not as big of a problem as it used to be with the internet.  Amazon has a big selection of Cal King accessories.)
  • Mattress stores stock King mattresses a lot more than California Kings. Whereas you can usually get a King mattress immediately, a California King might take a few weeks to arrive. (Note: This won’t necessarily be true if you live California. Because, well, you’re in California and it’s named after California, so it’s more readily available in California.)
  • As mentioned before, a King is bigger than a California King, so you have more space. If two people are sleeping in the bed, there will be less partner disturbance in a King. If you have a tosser/turner sleeping next to you, the extra overall space can make a difference in how much sleep each partner gets. Ditto if you allow kids or the dog to sleep with you.

Pros of a California King Mattress

Those are all compelling reasons to choose an “Eastern” King, but the California King would not exist if it didn’t offer different characteristics that serve other sleeper needs. For instance:

  • A California King is great for tall people. If you’re taller than about 6’3″ or so, your feet might hang off of a regular King. A California King gives you an extra 4 inches of length. One sleeper who is 6-4 recently commented on this site that he doesn’t sleep with cold toes anymore. That’s the difference a Cal King can make for tall people.
  • If you have slept in a King size waterbed, you were actually sleeping in a bed the size of a California King. So if you want to replace the waterbed mattress and keep the platform, you’ll need a California King mattress.
  • If you have a long, narrow bedroom, a California King might fit into the room a little better.
  • This one’s a bit of a stretch, but sometimes you can get a great clearance deal on California King mattresses. Some people get a California King special ordered, only to realize that they needed a regular King. That California King mattress might sit in the store’s warehouse for months, because California King are more rare. I’ve known people who paid under $600 for a $3500 California King mattress because it was discontinued for so long that the store just wanted to get rid of it.

What is a Split King Mattress?

Yes, another wrinkle. The Split King is roughly the same size as a regular King but it comes in two pieces instead of one. Basically it’s two twin-sized beds placed side by side on a single box spring, base, and/or frame. Everything we’ve said about the traditional King applies to the Split King.

Using a Split King is also great with an adjustable base. Each partner can adjust their mattress to their liking.

Also, we talk a lot about motion transfer here at Mattress Nerd. It is important. When partners share a bed, you want to feel as little of their movement as possible in order to sleep deeply and well.

When you have two mattresses on the base, it’s like two pockets of space that isolate movement and do a better job confining it to that area. Regular King size mattresses have one single area that must work to isolate movement from two people on the same slab.

cal king mattress

Pause & measure before you buy a larger mattress

Before you get too excited about buying a bigger bed, slow down and consider the actual space in your bedroom.

With a King or a Cal King in the room, can you still open the doors to the room and your closet? Will you still be able to walk around the bed? Do the drawers of your dresser and/or nightstand still open? Is the bed blocking anything important like the vents to the AC or the heater?

One way to visualize the space a King or Cal King will take up and determine if there is enough livable space is to use an online room planning tool. There’s one called the Roomsyler 3D Home planner that is available for use free of charge.

Also, speaking of weights and measurements, how big and tall are the people who will be using the bed? Taller people might find the Cal King a better fit. But heavier people may want more surface space that you get with a King for their wider bodies.

Consider the costs of the upgrade

If you’re upgrading from a queen-sized mattress, you’ll normally pay 15-20 percent more for an upgrade to either the King or the Cal King. But the same make and model of a King and the Cal King are usually priced the same across the board.

Also remember, if you’re going from a queen to any king, you’ll need new sheets, blankets, frame, platform, etc. It’s kind of the same principle when you lose a lot of weight: you gotta replace all of the things that don’t fit anymore.

Our Favorite King Mattresses

See all of our top picks for the best king mattresses!


Coined by some as "the internet's most comfortable mattress," this three-layer mattress is on the firmer side and suits back and stomach sleepers very well.
Puffy Mattresses

See our full Puffy mattress review for more info.

Helix Midnight Luxe

We rank the Helix Midnight Luxe among our best mattresses for side sleepers. Zoned support provides the hips, shoulders and neck with just the right amount of cushion to keep the spine aligned and ensure you wake up pain-free. Plus, it's 2 inches thicker than the standard Midnight.
Helix Midnight Luxe Mattress

See our full Helix Midnight mattress review for more info. 


For most people, a King sized mattress is a correct size to get. Don’t get a California King unless you have a very specific reason to do so (e.g. you’re exceptionally tall, you’re replacing a waterbed, etc). I hope this has cleared up this common misconception.