Difference Between King and California King Mattresses

Buying a new mattress that’s the right size can be a difficult experience, even when you’re shopping online and have all the information you could ever want at your fingertips. Unless you happen to have precise measurements of your sleeping space on hand, the dimensions of the mattress aren’t exactly helpful. And shopping by style isn’t any easier, with names like Twin, Double, and Queen being far from useful. But no two sizes illustrate this problem as well as the King and California King Mattresses, the troublesome pair of furniture royalty.

What is the difference between a King and a California King mattress? Believe it or not, it’s just a matter of a few inches: your regular King mattress is 76 inches wide and 80 inches long, whereas your California King mattress is 72 inches wide and 84 inches long. In somewhat simpler terms, a California King is four inches longer than a standard King size, but a King is four inches wider than a California King.

It really is that simple, but the slight differences between the two can lead to certain considerations you need to make to get the most use out of them. The first part of this guide will address these concerns to help you best determine which mattress fits your needs. The second part will answer common questions people have regarding the two sizes.

Which Size Is Right For Me?

On the surface level, you can just look at your height to determine which of the two is better for you. People who stand over six feet tall will probably be more comfortable sleeping on a California King-size given its extra length. But let’s assume you have more concerns than your height: what else should you take into mind?

When determining whether you’re better suited for a King or California King, you’ll be looking at usual questions associated with buying a new mattress. However, you’ll need to view them from a different perspective thanks to the California’s unique measurements. Most other mattress sizes are proportional to each other to some degree, but the California is unique in that its build has no direct comparison.

Sleeping alone or as a couple

If you sleep alone, you can enjoy the luxury of either King without need for further accommodation. If you happen to share your bed, however, the standard King’s extra width can be more alluring, especially if you or your partner are somewhat restless sleepers or just want the option of more personal space between you. This is just a matter of how the two of you choose to sleep—if neither one of you requires a great deal of space, the regular King could serve you just as well.

Dimensions of your room

Here’s where things can get more complicated. The space that your bed occupies can be just as important, if not more so, than your own size. It needs to fit wherever you plan on putting it. If you’re not careful, those extra inches that seemed so inconsequential before could make your bedroom feel more crowded.

One of the biggest things that is easily overlooked is a bed’s proximity to a heat source. It’s obvious when a mattress blocks a door, but how close can it be to a radiator or register before it becomes a problem? Because the four inches between both King sizes can seem so small when you upgrade from another size, you should try to maintain awareness of how close it is to heat sources as you set it up.

There are no perfect guidelines for how much space you should have between the sides of your bed and nearby walls and other furniture (like nightstands and dressers), but you need to be comfortable walking around it. Also, remember that with sleep we find comfort in habit and familiarity. If you end up having to place your mattress in a new part of the room because its measurements don’t work as well in your previous spot, it may take time for you to adjust.

The California King is more expensive

As one of the largest mattresses on the market (though not the de facto largest), it’s not a shock to learn that the California King is more expensive than the standard King. There’s a misconception that because the two sizes are so similar they must cost the same. Of course, this is hardly the truth, and if the price is s major factor in your decision making you should prepare yourself for the difference before you buy. Depending on the make and manufacturer, it can be fairly steep or relatively small.

It’s harder to shop for California King accessories

The California King is somewhat scarce compared to King size mattresses. It’s not exactly rare like a specialty mattress, but for several reasons, it’s not produced in the same numbers as its stateless counterpart and thus isn’t found as easily in brick-and-mortar stores. This being the case, it naturally follows that finding accessories for a California King can require a little more work.

Shoppers sometimes think that King and California King items, such as sheets and frames, are interchangeable. Not only will King sheets fail to properly fit a California King, but a King frame will not properly support a California King, leaving the mattress unbalanced and uneven. At best it’s frustrating and at worst it could be painful (in the case of the frame, anyway).

If you’re upgrading from a King to a California King, understand that you’ll need to upgrade everything else about your bed set up to accommodate it, including sheets, linens, frame, box spring, and even blankets (pillows don’t need to change). Even if you find your mattress in-store, it may be necessary (or easier) to purchase the other components online to remove the difficult task of actually locating them.

Motion isolation/transfer needs – This is only an issue if you share your bed with someone else. By design, every motion made on a mattress transfer throughout it. That means that if your partner moves, you may feel it and have your sleep disrupted.

A larger mattress is better at isolating the impact of these movements throughout itself. Because we sleep lengthwise, the King mattress is better and more suitable for motion isolation than its California counterpart. The matter does have more complexities than that, including the size of sleeping partners and their weight, but as a general rule of thumb, a wider mattress better helps to isolate movements.

That isn’t to say that a King size is the only solution, of course. You can find any size specifically engineered and made with materials that help absorb the disruptions caused by motion. It’s more expensive to purchase mattresses specifically made with motion isolation in mind, but the money may be worth it if you are particularly sensitive to your partner’s movements.

Those are the biggest factors you need to consider when choosing between King and California King Mattresses. Other issues largely come down to personal preference over functional needs, such as aesthetics or material used. Next, we’ll move onto commonly asked questions about the two sizes.

Does a California King require a foundation? 

The size of a mattress has nothing to do with whether or not it requires a foundation, be that a frame, box spring, or something else. Somehow, California Kings have developed a reputation for not needing a supporting foundation. It’s only true in the sense that you can place a California King directly on the floor with no support whatsoever, but the same is true for any mattress regardless of size.

A box spring serves to give your mattress additional support, and a frame gives you storage space beneath your bed while allowing more airflow around it. If you want to use either with a California King, you’ll need to purchase ones specifically for their size. Keep in mind that larger mattresses need more support, so platform and slatted frames are ideal for both varieties of King sizes.

What is a Split King mattress? 

If you’ve already started searching for a King size mattress, you’ve likely come across the Split King. The measurements are exactly the same as a standard King, but the mattress is literally two Twin-sized mattresses. They can be fitted with one King size sheet or two twins.

Despite being two separate mattresses, the two Twins fit into a single King frame and rest easily on a King box spring. The benefit of using two Twins in place of one King is that couples can customize each half differently. You can fit them with individual sheets to get the preferred material or texture, and you use mattresses of different firmness levels.

Buying a Split King set usually means the mattresses are identical. If you want each half to have separate levels of firmness, it will be easier to buy the Twins individually.

Is there a split California King? 

There is a California equivalent of the Split King. However, they are much more difficult to acquire. With the California King already under-produced in comparison to other sizes, the split variation is even harder to come across.

Unlike the Split King, you can’t reasonably build a California equivalent, either. No mattress equals half of a California’s width. Short of an adjustable mattress, a Split King is your best option for customizing the halves of your bed.

Are California Kings harder to clean and maintain? 

Again, the only thing that sets a California King apart from other mattresses are the measurements. Cleaning and maintenance are only superficially altered by the size, and the difference between standard and California is slight anyway. What determines cleaning and maintenance needs are the materials used to make the mattress itself.

If you’re concerned about keeping a California King clean, you can purchase covers that fit their unique measurements. Otherwise, just follow the manufacturer’s instructions for cleaning and caring for it.

Are all California Kings foam mattresses?

While most California Kings are made with some variety of foam (and the mattress industry continues to move more towards foam in general), there is a small number that uses the old metal spring design. One isn’t inherently better than the other, though safety concerns about spring-interior mattresses aren’t uncommon.

With all of that being said, if you have specific sleep or mattress needs, a California King will cause you more problems than other sizes. Its scarcity is reflected in the varieties sold as well as the ease of finding bedding accessories for it, and when you can find them they tend to be more expensive than other King-sized counterparts.

What are the Eastern and Western King sizes?

These are merely alternative names for King and California King, just in case you weren’t confused by the naming convention already in use. Eastern is standard King and Western is California King. Allegedly the California King moniker came from a furniture outlet in California, so the East/West labels may just be a reference to that. Ultimately its usage comes down to manufacturer preference.

Ultimately, the key difference between King and California King is one of height versus width. The California will give you more length to stretch out on, whereas the standard King has more width to move across. The function should be your first concern when buying a mattress, and unless you’re looking at specialty builds or materials, the dimensions alone should be your primary concern.

The California King will indeed be more of financial investment; if not for the mattress itself then for the additional purchases you’ll have to make to outfit it. You can, as always, shop around to mitigate the cost somewhat. But because the size is made in lower numbers compared to others; you may not always have access to the less expensive options. Price everything out beforehand so that you know you’ll be able to afford it. In the worst-case scenario, but the mattress first and lay it on the floor while you wait to get the remaining pieces.