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 mattressBasically, they don’t. Let’s break it down here:
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.
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.
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:
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:
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 mattress 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.
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 to 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.
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.
For most people, a King sized mattress is the 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.