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

One of the best mattresses available in both full and California king sizes is the Amerisleep AS3. It works well for all types of sleepers in all types of mattress sizes. Need a bed for your child or preteen? Try the AS3. Need a bed for guests? Try the AS3. Need a bed for you and a partner? Try the AS3. The opportunities are endless with the AS3.

Inside the AS3 is our Bio-Pur® memory foam. Most memory foams are made from petroleum, which results in chemical-smelling, hot, and sag-prone mattresses. Bio-Pur® is made mostly out of castor oil, resulting in a durable, breathable, and fresh-scented bed. It relieves pressure just as well as other memory foam mattresses, but it won’t cause you to sink in bed.

The AS3’s second layer is made from Affinity foam and features HIVE®, our support technology with five ergonomic zones. HIVE® helps evenly distribute your body weight to reduce pressure point pain.

At the bottom of the AS3 is Bio-Core® foam, which supports your spine and prolongs your mattress’s lifespan.

Another great part of the AS3 is that it comes in both foam and spring variations. The AS3 Hybrid contains pocketed coils and a thin foam base instead of Bio-Core®, resulting in a uniquely springy and supportive bed.

All Amerisleep mattresses, including the AS3, include free shipping and returns, a 100-night trial, and a 20-year warranty.

Quick Summary

• Comes in both foam and spring models
• Amerisleep’s best-selling mattress
• Has a balance of support and cushioning

A great full-size mattress option is our Organica mattress, a sustainably-produced bed great for all sleepers. At 13 inches thick, the Organica has a medium feel and contains wool, two types of latex, and pocketed coils.

At the top of the Organica is New Zealand Joma Wool®, which isn’t just another layer of cushioning. Wool is both a natural thermo-regulator and fire retardant. This means sleeping on wool will keep you and your bed both cool and safe in the event of a fire.

Next is a Talalay latex comfort layer. It’s breathable and springy, yet still soft and pressure-relieving. It’s not quite as “hug-like” as memory foam, but it makes up for this with its extra bounciness.

We use pocketed coils in the Organica to take it to another level of breathability, supportiveness, and bounciness. The steel springs isolate motion while offering isolated support for your spine and back. Beneath the coil layer is Dunlop latex, which protects the springs and maintains your bed’s structural integrity.

We sought four certifications for the materials inside the mattress:

• Cotton: Certifed organic by Global Organic Textile Standard (GOTS)
• Wool: Certified by Standard 100 by OEKO-TEX®
• Latex: Certified by Standard 100 by OEKO-TEX®, Rainforest Alliance, and eco-INSTITUT

Like all Amerisleep mattresses, the Organica comes with a 100-night sleep trial and a 20-year warranty.

Quick Summary

• Contains both natural Talalay and Dunlop latex
• Made with organic and sustainably-sourced materials
• Free of fiberglass and chemical flame barriers

The most luxurious California king size mattress we offer is the Amerisleep AS5 Hybrid. It’s our softest and thickest mattress, yet we manage to make it supportive and cooling.

Inside the AS5 Hybrid is Bio-Pur® memory foam, the same material in the AS3 we mentioned earlier and in many other Amerisleep beds. What makes the AS5 Hybrid different from our other beds is its Active Flex transition layer.

Active Flex is a latex-like material designed to enhance the AS5 Hybrid’s softness and support without making it feel overly firm. It prevents you from sinking into bed uncomfortably as well, making this bed one of our favorites for plus-sized people.

Beneath the Active Flex are hundreds of pocketed coils and base foam. The AS5 Hybrid is another one of our beds available in a foam model as well if you prefer less bounce and more cushioning. In the standard AS5 mattress, there is Bio-Core® foam rather than pocketed coils.

The AS5 is backed with a 100-night sleep trial and a 20-year warranty.

Quick Summary

• Comes in both foam and spring models
• Soft, yet supportive for all sleepers and body types
• Contains flexible and motion-isolating coils

Size Comparison of California King and Full Size Mattresses

A California king bed is 18 inches wider and 9 inches longer than a full bed, making it a good choice for couples.

A full bed doesn’t provide adequate space for a couple, but it is a good option for single sleepers who don’t have the budget or space for a queen bed in their room, like young adults living in a studio bedroom apartment.

Other Standard Sizes

If the California king or the full size does not suit your sleep needs, there are other popular mattress sizes available online or in mattress stores. When buying a mattress, factor in the space taken up by other essential bedroom furniture such as lamps, nightstands, and a dresser.

Ideally, leaving 2 to 3 feet of space on all three sides (except the side against the wall) of your bed makes your room look neat. This set-up also leaves you with sufficient walking space. Following are the other standard mattress sizes:

Twin Size Mattress

Dimensions: 38 inches by 75 inches

A twin size mattress is 16 inches narrower than a full so they don’t need as much room space. This compact size mattress can even fit in a room measuring 7 feet by 10 feet, but its short length cannot accommodate tall sleepers. A twin is the same length as a full bed.

A twin bed is a good option in a child’s room. A child usually graduates from a crib to a twin bed. Families with more than one child often use bunk beds available in twin and twin XL sizes.

Twin XL Size Mattress

Dimensions: 38 inches by 80 inches

A twin XL size mattress is 5 inches longer than a twin and full, making it a better choice for taller people. The extra length comes in handy to accommodate growing teenagers as well. Twin XL beds are common in children’s rooms, college dorm rooms, and shared bedrooms.

See our twin vs twin XL mattress guide if you want an in-depth comparison of the two sizes.

Queen Size Mattress

Dimensions: 60 inches by 80 inches

A queen size bed is 6 inches wider and 5 inches longer than a full. It’s the ideal option for single sleepers because it allows sufficient space to stretch out while sleeping. The queen bed is also used as a couple bed, allowing each sleeper 30 inches by 80 inches of space. Though a queen is not as spacious as a Cal king bed, it’s the right size for couples who don’t have large bedrooms for bigger beds.

Full and queen mattresses are often compared to each other because of their similar dimensions.

King Size Mattress

Dimensions: 76 inches by 80 inches

A king size mattress is the widest of all standard size mattresses. It is 4 inches wider but 4 inches shorter than a Cal king. A king bed is the perfect size for couples and it has enough room for small children as well.

Like Cal king beds, even standard king size mattresses are also available in split options. Since a twin XL mattress is the exact half of a king bed,  placing two twin XL mattresses side by side makes a split king mattress.

FAQs

Which is a better option: a king or California king?

Both king and Cal king size beds have plenty of room for a couple, but a Cal king is 4 inches longer than the king. If you or your spouse need some extra legroom, a Cal king is a good option. Otherwise, a king size mattress is better because it is 4 inches wider than a California king size bed. If children want to sleep with parents some nights, then a king will be more spacious than a Cal king. Plus, the total surface area of a standard king is more than a Cal king bed.

Do two twin XL beds make a California king bed?

No, two twin XL beds placed side by side makes a king bed. A twin XL mattress is the exact half of a king bed, so placing two of them together makes a king, but a Cal king has different dimensions. A Cal king bed is narrower and longer than a king, so two twin XL mattresses will not add up to the size of a Cal king bed.

Do king size sheets fit a California king bed?

No, king sheets will not fit a Cal king bed. A standard king bed measures 76 inches by 80 inches, while a Cal king bed is 4 inches longer and narrower. A fitted sheet meant for a king bed will be too short and wide for a Cal king mattress. Cal king sheets are readily available online or in bedding stores. A Cal king is a standard mattress size, so finding compatible bedding accessories is not difficult.

Is a full size bed good for couples?

No, a full size does not have adequate space for a couple. It can fit an adult and a child but will be too small for two adults. In fact, some couples feel cramped even in a queen, which is 6 inches wider than a full bed.

Is a full size bed the same as a queen?

No, a full size bed is 6 inches narrower and 5 inches shorter than a queen. A full mattress is a good option for single sleepers who don’t have sufficient space for a queen, while a queen size mattress can be used by both single sleepers and couples. Though a queen bed is not the best option for couples, it’s the right fit in small master bedrooms.

Conclusion

The Cal king and the full cater to different sleeper needs. While the Cal king is always the best option for tall sleepers because no one likes to sleep with their feet dangling out of the bed, the full size mattress is good for average size single sleepers. Finding the right size mattress for yourself is crucial to a good night’s sleep. If you don’t get enough space to stretch out and relax your muscles while sleeping, your sleep quality gets affected and poor sleep causes daytime drowsiness, impairing productivity.