California King vs. Full Mattress: What’s the Difference?

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When it comes to dimensions, the California king size bed and the full bed couldn’t be more different. One is great for average-height single sleepers who like to toss and turn, while the other is designed with couples and super-tall people in mind. 

If you’re in the market for a new mattress, you probably know whether you need a larger or smaller bed, but do you need a California king or a standard king? Do you need a full bed or queen bed? Below, we’ll go through the dimensions of the California king, the full, as well as other common bed sizes, and we’ll talk about how to choose the right one for you.

California King Size Mattress

Like the state of California, the California king is long and narrow when compared to the standard king. In fact, the California king is the longest of the standard bed sizes at 84 inches—that’s a full 7 feet! California kings are also a full 6 feet (72 inches) wide. This means they’re great for couples who need extra legroom, like if one partner is really tall.

Room Dimensions for a California King Mattress

In order to have enough clearance to get around your bedroom, you need about 2 feet of space around 3 sides of your bed. For the extra-long Cal king, that means you need a bare minimum of 9 feet of length in your bedroom and 10 feet of width. However, 9 feet is usually not sufficient to accommodate a California king. 

A too-small bedroom can leave you with a cramped look, and you won’t have enough space for furniture. That means a 10 by 12 or 12 by 12-foot room will be more suitable for a California king. That way, you’ll have sufficient room for a dresser, extra seating, or whatever else you want.

Who Should Sleep on a California King Bed?

The people who will benefit most from a California king are those well over 6 feet tall. If you’re used to your feet hanging off the edge of the bed, a Cal king will likely be up your alley. The California king might also be a good option for couples who need extra space at the foot or head of the bed—like if you use a bunch of extra pillows. 

California King vs. Standard King

The standard or eastern king was designed for width, while the California king was designed for length. Couples with one or more active sleepers might do better with a standard king than a California king, as it offers an extra 4 inches of width. However, if you’re extra-tall, even a king might not be a good choice for you, as the standard king is no longer than the queen or twin XL.  

Full Size Mattress

If you’re looking for a more compact bed, a full mattress will definitely fit a smaller space better than a Cal king. At 54 by 75 inches, the full is 18 inches narrower and 9 inches shorter than the California king. That means it won’t be comfortable for sleepers over 6 feet tall. For everyone else, the full is a great option if you’re wanting some extra wiggle room but don’t have the space to accommodate a bigger bed.

Room Dimensions for a Full Mattress

A full is small enough it can fit just about any bedroom. Since it’s only 4.5 by a little over 6 feet in size, you can put it in a space as small as 8 by 9 feet. However, a full in a room this small may look cramped. You also won’t have enough space for furniture. If you want a chest of drawers, vanity, etc., you’ll need a room of at least 8 by 10 or 10 by 10 feet. 

Who Should Sleep on a Full Bed?

If you’re tired of feeling restricted on a twin, a full could be a good step up. At only 38 inches wide, twins don’t offer a lot of width to combo sleepers. The full adds 16 inches on top of a twin’s width, meaning single, active sleepers especially may enjoy the wiggle room of this bed size.

One thing to keep in mind about the full is its reduced length. If you replace your twin XL with a full, you’ll be losing 5 inches of extra length. Sleepers under 6 feet tall likely won’t notice the difference, but if you’re over 6 feet tall, you might be better off upgrading from a twin XL to a queen.

Full vs. Queen 

The queen size mattress is 6 inches wider and 5 inches longer than the full. That makes it suitable not just for taller single sleepers, but for couples as well. While a full really doesn’t provide the width necessary to accommodate two sleepers, a queen will be comfortable for most couples unless they like to toss and turn or spread out during slumber.

Other Mattress Sizes

There are plenty of mattress sizes besides the Cal king and full bed. We’ve talked a little about the standard king and queen, but let’s dive a bit deeper. 

Twin Mattress

If you want a compact bed, the twin bed is the smallest of the standard mattress sizes. At only 38 by 75 inches, the twin is perfect for dorm rooms, multi-purpose guest rooms, and studio apartments. Just remember the twin won’t accommodate you if you’re over 6 feet tall. 

Twin XL Mattress

Taller sleepers who want the compactness of a twin may enjoy the twin XL. At 38 by 80 inches, the twin XL will still fit in small bedrooms, but it won’t leave your feet hanging if you’re over 6 feet tall. 

Queen Mattress

At 60 by 80 inches, the queen is the most popular bed size because it fits perfectly in most bedrooms. Kids’ rooms, guest rooms, and smaller master bedrooms are all usually a good fit for queen beds. 

Queen mattresses are a good option for tall single sleepers who want some additional wiggle room, couples who don’t need a king’s extra width, and anyone wanting to fill out a bedroom left looking empty by a twin/twin XL.  

King Mattress

The standard king mattresses are the largest bed size by surface area, even though it’s 4 inches shorter than the California king. At 76 by 80 inches, the standard king offers the most width as well as surface area. This makes it the ideal choice for couples who need extra space. A king is also a good option if you have a large master bedroom that needs to be filled out. 

Mattress Types

No matter the size, a bed is only as good as its mattress. A high-quality mattress is the single most important part of a good night’s sleep. There are four basic types of mattresses: memory foam, latex foam, innerspring, and hybrid, and each of these mattresses has its own strengths and weaknesses.

Memory Foam

Memory foam is a special type of polyurethane foam made to go in mattresses, pillows, and other furniture. Of all the mattress materials, memory foam is the most cushioning and supportive. It conforms to the unique shape and position of your body to relieve your pressure points while supporting your spine, promoting ideal alignment. 

However, memory foam has a couple of issues. First, its slow response time may not be ideal for sleepers who move around throughout the night, as it takes a long time to bounce back to its original shape. Heat retention is also a problem for some. While modern memory foam mattresses are much cooler than it was in the past, memory foam is still warmer than other mattress materials. The addition of gel improves memory foam’s temperature-regulating ability, but without the circulation of a hybrid or innerspring, memory foam is still too warm for some. 

Latex Foam

If it’s an organic mattress you’re after, latex might be the best option for you. Latex is made from the processed sap of the rubber tree. If you don’t like memory foam’s lack of responsiveness, latex could be a good alternative.

Latex bounces back much more quickly than memory foam, which can be a lot more comfortable for you if you’re an active sleeper. Latex is also naturally cooling, so it doesn’t need a bunch of additives and processing techniques to keep you cool all night. Maybe best of all, latex is highly durable, meaning a latex mattress will outlast just about any other.  

On the flip side, latex doesn’t contour as well as memory foam, meaning it won’t offer as much pressure relief or support. Latex is also the heaviest of all the mattress materials, so if you move a lot, latex can be a pain.



One of the oldest modern sleep technologies, innerspring mattresses employ a network of coils that act as a support for sleepers. This coil system is usually covered by a thin layer of plush material like cotton, wool, fiberfill, etc. Innersprings are the coolest, lightest mattress type, and they’re also highly responsive, so if you like bounce, you might enjoy an innerspring. 

Innersprings do have their issues, though. For one thing, they don’t have much cushioning, so the pressure from the coil system can cause pain in your hips or shoulders. For another, innersprings don’t have much contouring ability, meaning they can’t offer custom support. Innersprings also wear out faster than any other mattress type because their coil support systems lose tension and break down. Some innerspring mattresses last as little as 6 years. 


As its name suggests, a hybrid mattress combines the responsiveness of a coil network with the cushioning power of foam. Hybrids contain a pocketed coil support system topped by at least 2 inches of plush foam for a comfort layer. Hybrids can have latex, memory, or any other type of foam, meaning they offer a lot of variety. You can have the springiness of latex or the contouring ability of memory foam, and they’ll both have the increased responsiveness and airflow of the pocketed coil support layer.

Hybrids combine the best attributes of foam beds and innersprings, but they do have their drawbacks. For one thing, the pocketed coils in a hybrid last longer than an interconnected spring system, but all coils break down faster than foam support, so your hybrid might not outlast a pure foam mattress. Hybrids also are the most expensive of all the bed types, usually costing much more than foam or innerspring beds of comparable quality. 


Can tall sleepers use other bed sizes besides the Cal king?

The king, queen, and twin XL are all 80 inches in length. That’s over 6.5 feet long, so unless you’re well over 6 feet tall, you should be able to sleep comfortably on any of the 80-inch sizes. You probably won’t truly need a California king to accommodate your height unless you’re 6 feet 4 inches or taller.

Can two people sleep on a full size bed?

A full is also called a double bed because it’s technically big enough for two people, but it’s not comfortable for most couples to sleep on long-term. At 54 inches, it offers two adult sleepers 27 inches apiece, or the same width as a baby’s crib. This width leaves almost no room for any kind of movement and will expose both partners to a lot of disturbances throughout the night. For that reason, it’s better to use full beds for children and single adults.  

What’s a split king size mattress?

A split king mattress is a standard king size bed that’s cut down the middle. You can split a king by putting two twin XL bases and twin XL mattresses together in the same standard king bed frame. Split kings are great for couples who want to sleep in the same bed but have different firmness/material preferences or adjustable base settings. 

However, split kings stick to the standard king’s dimensions. While you can get any pair of twin XL mattresses and any pair of twin XL bases to fit a standard king’s frame, if you want a split California king, you’ll have to buy a setup specifically made for that purpose. 

Should I use box springs for my California king?

Box springs come in all bed sizes, but if you get a mattress other than an innerspring, you can’t put box springs underneath it. The weight of memory foam, latex foam, or hybrid mattresses is too much for box springs to handle. They will compress under the mattress and wear out too quickly. They might even break. What’s more, many mattress manufacturers state putting their foam or hybrid product on box springs can void its warranty.

It’s better to put your mattress on a more rigid support like a mattress foundation or platform bed. These bed bases feature slats rather than a coil network, meaning they offer much firmer support that’s able to take heavier mattresses like memory foam and latex. They’ll also last longer than box springs. 

Can you put a California king mattress in a king bed frame?

No. A California king is too long and too narrow for a king bed frame. If you already have a king bed frame, you’ll have to either replace your king mattress with another standard king one or buy a California king bed frame. 

Bottom Line

As we’ve seen, there are a lot of differences between the California king and the full size bed. When it comes to the duel between these two mattresses, finding the best mattress for you is going to depend more on your height, the number of sleepers sharing your bed, and your room dimensions than on your personal preferences. 

Regardless of the size, the most important factor in getting a good night’s sleep and waking up pain-free is the quality of your mattress. If you don’t have a supportive, cushioning mattress, it doesn’t matter what size bed you get. 

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