Quick answer: King (76″x80″) offers maximum width for couples, families, and active sleepers. Cal King (72″x84″) provides extra length for tall sleepers but sacrifices width. Choose King unless height over 6’2″ is primary concern.
| Feature | King | California King |
|---|---|---|
| Dimensions | 76"W x 80"L | 72"W x 84"L |
| Total Area | 6,080 sq in | 6,048 sq in |
| Best For | Couples, families, active sleepers | Tall sleepers (over 6'2") |
| Width per Person | 38" each | 36" each |
| Room Size Needed | 13'x13' minimum | 12'x14' minimum |
| Bedding Availability | Widely available | Limited, more expensive |
| Best Choice If | Want maximum width | Need extra length only |
Key Takeaways
- Size misconception: Cal King isn’t bigger – it’s 32 square inches smaller than King with narrower width
- Height threshold: Only choose Cal King if someone is genuinely over 6’2″ and needs extra length
- Width matters more: King’s extra 4″ width significantly impacts couple comfort and active sleepers
- Practical considerations: King has better bedding availability and lower accessory costs
- Quick links: Compare also king and split king mattresses. Consider also how to style your king bed.
Some people mistakenly believe California kings are bigger than standard king beds, but the main difference is actually in the width and length.
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California kings are longer and narrower than standard kings—a king bed is 76 inches by 80 inches, and a Cal king bed is 72 inches by 84. As a result, tall sleepers or couples with narrower master bedrooms often choose California kings.
In our article, we discuss the differences between a king and California king size bed, and include the pros and cons of both sizes to help you determine which mattress size is right for you.
What Is a King Size and Who Should Choose It?
A king size mattress measures 76 inches by 80 inches —the equivalent of two twin XL beds placed next to each other. A king-size bed (otherwise known as an Eastern king) is designed to accommodate two sleepers but has room for children who like to snuggle with their parents at night.
The standard king size bed is the largest mattress size on the market, covering a total surface space of 6,080 square inches. An Eastern king bed size is a popular choice for couples, second only to the queen size bed.
A king mattress requires a bare minimum of 12′ × 10′, but this will feel cramped. For comfortable daily use, we strongly recommend at least 13′ × 13′ to allow proper furniture placement and easy movement around the bed.
When mentally fitting a king mattress into your bedroom, account for:
- 2-3 feet of walking space on three sides of the bed
- Room for nightstands (typically 24-30″ wide each)
- Space to open dresser drawers if placed at the foot of the bed
- Comfortable access for making the bed and changing sheets
Important consideration: While these large mattresses offer luxurious sleeping space, cramming them into undersized rooms can make your bedroom feel claustrophobic and difficult to navigate.
If your room is smaller than the recommended dimensions, consider whether a queen mattress might provide a better balance of sleeping comfort and livable space.
Pros
- Couples who like to stretch out, plus room for children
- Large bedrooms
- Widely available
- Split king option available for couples with differing sleep preferences
Cons
- Expensive
- Too big for limited spaces
- Hard to move due to size and weight
What Is a California King Size and When Do You Need the Extra Length?
A California king mattress (also known as a Western king) measures 72 inches by 84 inches. This mattress size is also great for couples, especially for sleepers over 6 feet tall. Since the Cal king mattress is more narrow than a king size, it may have room to fit 1 to 2 small children in addition to two adults.
California king beds are the second-largest standard size in the mattress industry with 6,048 square inches of total surface area. California king mattresses need a minimum of 12′ × 12′, but 12′ × 14′ or larger provides much better functionality and comfort.
When planning for a California king mattress in your bedroom, account for:
- 2-3 feet of walking space on three sides of the bed
- Room for nightstands (typically 24-30″ wide each)
- Extra clearance at the foot due to the mattress’s 84″ length
- Comfortable access for making the bed and changing sheets along the longer sides
- Additional space if placing furniture like a bench or storage chest at the foot of the bed
The key difference is that California kings require more length-wise planning due to their extra 4 inches, which can affect furniture placement at the foot of the bed and impact how you navigate around the longer perimeter when making the bed or accessing storage.
Pros
- Tall people at least 6 feet
- Couples who like to be closer together
- Split California king option for couples with differing sleep preferences
- Large bedrooms
Cons
- Hard to move due to bulky size
- Higher price tag
- Difficult to find bedding
How Do I Choose Between King and Cal King?
Stuck between the two? Here’s the quick lowdown!
Choose King If:
- Either partner under 6’2″ tall
- You prioritize maximum sleeping width
- You have active sleepers or frequent position changes
- Children/pets join you in bed
- You want widely available, affordable bedding
Choose Cal King If:
- One or both partners over 6’2″ tall
- Your bedroom is narrow but long
- You sleep close together as couple
- Height is your primary comfort concern
Red Flags for Cal King:
- Choosing for “bigger” bed (it’s actually smaller total area)
- Neither partner has height issues
- You’re active sleepers who need width
- Budget constraints (bedding costs more)
- Don’t have the proper frame (you don’t want the mattress hanging over the sides)
Which Amerisleep Mattresses Work Best in King and Cal King Sizes?
Along with the regular king and the California king size mattresses, we also offer split king size mattresses of all our models. Any one of these three sizes can suit a sleeper who wants to upgrade to a larger bed, but the key is to choose the right mattress for their needs.
Quick Guide: A 30-Second Summary
| Best King Mattress Overall | Amerisleep AS3 |
Best King Mattress Overall
Amerisleep AS3
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Price Range: $999 to $2148
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Mattress Type: Memory Foam
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Mattress Firmness: 5 to 6 out of 10 (Medium)
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Mattress Thickness: 12 Inches
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Available In: Twin, Twin XL, Full, Queen, King, California King, Split King
- Memory foam cradles one or two sleepers with ease
- Targeted support helps with a good spine alignment
- Sturdy foam core structures the mattress
- Side, back, and combination sleepers
- Couples and solo sleepers
- Hot sleepers
The AS3 mattress is easily our most popular model, and it owes much of its success to its versatile feel. Couples often seek a mattress like our AS3 when they’re searching for a king size mattress. The AS3 suits most sleeping styles, so two people can compromise without giving up what makes each of them feel comfortable.
The medium feel balances pressure-relieving cushion with supportive features and can support different sleeping positions and body types. The AS3 may be just what you need if you want to upgrade your bedroom with a king size bed, whether it’s a regular king or a California king.
Three foam layers make up the AS3 mattress, regardless of what size of mattress you choose:
- 3 inches of Bio-Pur® foam
- 2 inches of Affinity foam with HIVE®
- 7 inches of Bio-Core® foam
The top layer is Bio-Pur® foam, a plant-based material. While traditional memory foam is wholly synthetic, we replace some petrochemicals with plant-derived oils. As a partly plant-based memory foam, Bio-Pur®improves upon many qualities of traditional memory foam, aside from just its sustainability.
Thanks to its construction, Bio-Pur® adapts within seconds to a person’s movements, making it easy to move across the surface. The design of Bio-Pur® foam also promotes airflow through the surface, which enables heat dispersion for uninterrupted sleep.
Next, is the Affinity foam with HIVE® layer. Affinity foam has hexagonal cutouts arranged in five distinct zones. The hexagons in the shoulders and hips areas are placed to establish pressure relief and increase cushion, while the head, torso, and feet are focused on pure support.
The Bio-Core® foam base helps the mattress stand up against years of wear and tear, a particularly beneficial feature when it comes to making an investment on a king size mattress. After all, you don’t want to pay a king’s ransom for a king mattress only to have it sag within a few short years.
We designed the Bio-Core® foam to minimize the chances of sagging. Just how confident are we in the durability of Bio-Core®? Well, Bio-Core® foam is the main reason we back all of our memory foam mattresses with a 20-year warranty.
Quick Summary
- Medium feel supports people with conflicting sleep styles
- Five support zones for adaptable comfort and pressure-relieving cushion
- Sag-resistant, supportive base foam for greater mattress durability
What Factors Should You Consider When Choosing Between King and Cal King?
Whether you choose a king or California king size mattress, look at room dimensions, cost, and sleeper height. Also, take into account if you’re part of a couple that likes to sleep close to each other or prefer more personal space.
How King vs Cal King Choice Affects Sleep Quality
Movement Space: King’s extra 4″ width provides significantly more space for active sleepers and couples who move during sleep. Cal King’s narrower width can feel cramped for restless sleepers despite extra length.
Partner Comfort: King offers 38″ per person vs Cal King’s 36″ – the difference matters for couples who sprawl or need personal space during sleep.
Height Consequences: Sleepers over 6’2″ on King mattresses experience feet hanging off, disrupting circulation and deep sleep cycles. Cal King’s 84″ length prevents this issue but at cost of width.
Room Dimensions
Allow at least 2 feet of space on three sides of the mattress for more room to walk around and space to add furniture without feeling overcrowded. If you have a narrower room, a California king sized mattress might be better to save on space compared to a king size. If you plan to install a headboard, consider the space that will take up as well.
If you’re limited on space, then a queen mattress might be the better option —the queen size provides room for couples and is also a good choice for single adults. If you’re looking for a bed for one sleeper, queen or full size mattress are excellent options.
King Layout Needs:
- Minimum 13’x13′ for comfortable use
- Wider nightstand spacing required
- Better for square bedrooms
Cal King Layout Needs:
- Minimum 12’x14′ for comfortable use
- More length clearance at foot of bed
- Better for rectangular bedrooms
- Consider furniture placement along longer sides
Cost
Both king and California king mattresses have the highest cost on the market due to their large size and the number of materials they contain, particularly if they have a taller mattress thickness.
Since Cal king mattresses aren’t as widely available as a king-size, you may end up paying more. This also applies to accessories, like bed frames, comforters, and bed sheets.
Hidden Costs of Cal King Choice
Beyond initial mattress cost, Cal King ownership involves:
- Bedding premium: 20-40% more expensive than King bedding
- Limited selection: Fewer style and brand options, especially with adjustable bed sizes
- Specialty items: Mattress protectors, toppers cost more
- Replacement difficulty: Harder to find a new mattress in stores when needed
Sleeper Height
Height is another important factor to consider before choosing between a king and a California king mattress. How tall you are directly affects how comfortably you can stretch out on a sleeping surface, with shorter people having an easier time of it.
The Height Decision: When Cal King Actually Matters
Many people overestimate their need for Cal king length. Standard king at 80″ accommodates most sleepers comfortably:
- 6’0″ and under: King provides ample length with better width
- 6’0″-6’2″: King still sufficient for most, Cal King optional
- 6’2″ and over: Cal King becomes genuinely beneficial
- 6’4″ and over: Cal King strongly recommended
And your sleep position matters too! Side sleepers often need less length than back/stomach sleepers due to natural curling.
Couples
If you’re part of a couple and trying to decide between a king or California king mattress, consider how you both like to sleep —if one or both of you prefer more personal space, a king-size mattress is a good option. If you both like to sleep close to each other, a Cal king size bed is a great choice.
Of course, some couples don’t want to share the same bed because their comfort preferences are so different, but they may still wish to stay close at night. For these couples, we recommend the split king mattress, which gives each partner their own twin XL size mattress laid side by side.
These can even be a dual firmness mattress, with two twin XL mattresses offering unique feels for each person. Such partners can even have separate blankets for couples for further individualized comfort, though others may want king sheets and blankets over their twin mattresses for a uniform look.
Mattress Foundation
The type of foundation you use with the bed is more dependent on the mattress type, not the size. You can use an adjustable base with both kings and Cal kings, as well as box springs, platform beds, or slatted frames.
Just make sure you use the right bed foundation with your mattress type, which should be specified in the mattress warranty.
Other Standard Mattress Sizes
While king and California king mattresses are the pinnacles of expansive comfort, they’re not the right mattress choice for everyone. If you don’t have the room space or budget for either, there are four other standard sizes to consider.
| Mattress Size | Mattress Dimension | Recommended Room Size |
|---|---|---|
| Queen | 60 inches by 80 inches | 10 foot by 12 foot |
| Full | 54 inches by 75 inches | 10 foot by 12 foot |
| Twin XL | 38 inches by 80 inches | 10 foot by 10 foot |
| Twin | 38 inches by 75 inches | 10 foot by 10 foot |
Twin
The smallest size mattress an adult can comfortably sleep on is a twin size mattress. It’s an affordable option for sleepers under 6 feet tall, able to squeeze into most smaller bedrooms and studio apartments. However, for taller sleepers, it may be worth the extra cost to get a twin XL bed instead.
See also twin vs twin XL mattresses.
Twin XL
The twin XL mattress is a small step up from the standard twin mattress, giving taller sleepers more room to stretch out with their legs. If you’re an adult sleeper looking for a compact yet comfortable mattress, a twin XL size mattress might be your best option.
See also twin XL vs. split king mattresses.
Full
A full size mattress, occasionally referred to as a double bed, is excellent for sleepers who want a smaller mattress with room to sprawl. Despite its alternate name, we can’t recommend a full or double bed to sleepers who plan to share with a partner. Each person would end up with a sleeping space roughly the size of a crib mattress.
See also:
Queen
The queen size mattress is the largest mattress of the four smaller sizes, and it is the only one we would recommend to couples who aren’t considering king mattresses.
Measuring 60 inches wide and 80 inches long, a queen bed can provide enough space for two people to sleep without feeling pressed too close. Still, those who enjoy their personal space at night might prefer one of the king beds.
See also:
FAQs
Is a California king bigger than a regular king?
The king size mattress has a greater total surface space than a California king size —6,080 square inches compared to 6,048. Still, for many sleepers the difference is negligible.
How much bigger is California king than a queen?
A California king size mattress measures 72 inches by 84 inches. Meanwhile, a queen size measures 60 inches by 80 inches.
What is the point of a California king bed?
With a California king, each sleeper (or single sleepers) still have plenty of space, but the bed doesn’t take up as much room width-wise. And it gives taller sleepers more foot room.
What is an Alaskan king bed?
An Alaskan king measures 108 inches by 108 inches, or 9 by 9 feet. Alaskan kings are rare, but the largest variation of king beds.
Why is it called a California king?
The California king got its name from where it was invented—Los Angeles, California. It’s sometimes also called the Western king since it was made in the western U.S.
Is Cal King really better for tall people?
Only if you’re over 6’2″. Most people under 6’2″ sleep comfortably on King with better width benefits.
Will Cal King feel cramped for couples?
Yes, if you’re used to King width. Cal King provides 2″ less per person, which couples notice during sleep.
Should I choose Cal King for bigger master bedroom?
No. King provides more total sleeping space. Choose Cal king only for height needs, not room size.
The Perfect Size
Both king and California king are the largest standard mattress sizes on the market. Both are excellent choices for a master bedroom in providing adequate sleeping space.
While a standard king mattress is wider and shorter, a California king size is longer and narrower. Either can be the most comfortable mattress for you, whether you’re sleeping alone or with a partner.
Depending on your personal preferences and available space, both king size beds are excellent choices for any master bedroom.
About the author
McKenzie Hyde is a Certified Sleep Science Coach and a full-time writer specializing in sleep health and the mattress industry. With a Master of Arts degree in literature and writing from Utah State University, McKenzie combines her passion for writing with her in-depth knowledge of sleep science. Her articles cover a wide range of topics, including best sleep practices for students, the consequences of sleep deprivation, and choosing the right mattress for back pain relief. McKenzie's dedication to delivering accurate and informative content makes her a valuable contributor to the field of sleep health.
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