Mattress Sizes: King Bed Dimensions

There are some important considerations to be mindful of when choosing your next mattress. Bear in mind that this purchase ought to last you around ten years, your life can change a lot in that time. Let’s talk about King bed mattress sizes and determine if it’s right for your sleep space and lifestyle when wondering what size bed should I get

King size mattress dimensions make it the ideal choice for most people as it offers a luxurious amount of space to enjoy

What are the Dimensions of a King Bed and Mattress? - (in comparison to other sizes)  

King Size


AirFoam™ 10" Original



AirFoam™ 12" Signature


Total Sleep Area


Space per person



How Does the King Size Bed Compare With Other Bed Sizes?


Dimensions (Inches)


10” Original 

Dimensions (Inches)


12” Signature

Total Sleep Area

Space for Person

Ideal for






children over 2 years, preteens, guest rooms

Twin XL





Adjustable beds, dorm rooms, guest rooms






1 child with a pet or person of petite  stature 






Couples who sleep close or singles who like lots of space






A couple who enjoys plenty of space

California King





A person of tall stature


Should You Buy a King-Size Bed?

King size mattress dimensions make it the ideal choice for most people as it offers a luxurious amount of space to enjoy. It’s easy to find sheets and bedding to fit in a plethora of styles and colors. 

King size bed measurements are 76”x80”

Who’s Using the Mattress? 

The dimensions of a king size bed are perfect for couples who enjoy some personal space in the bed, with plenty of room left over for your small children or pets to jump on board for a snuggle. A single person will benefit from a king size mattress too, giving you plenty of space to starfish.   

Size of the Room

The measurements of a king size bed may engulf a small room. Be mindful of your bedroom dimensions before you choose a king size mattress. You will want to make room for nightstands, walk space, and other items you need in your bedroom.  

Location of the Bedroom 

Is your bedroom up many flights of stairs that are tight to maneuver? If so, shop with a reputable online mattress retailer who will ship your mattress rolled up in a box. This will make sure the mattress will easily reach your bedroom. A foam mattress can not be rolled back up but it will be easier to maneuver down the stairs.


Bed size, durability, and price are important factors to consider in your mattress search. You don’t need to spend thousands of dollars on a quality mattress. Set a realistic budget that doesn’t put pressure on you. Ensure you choose a reputable company that offers free delivery and easy returns with a lengthy warranty.  

The Benefits of a King Bed 

  • More space means more comfort 
  • Great for those who move around a lot as they sleep 
  • Families love to snuggle on king size beds 
  • Designed to alleviate sore pressure points
  • Easily match any bedroom aesthetic  
  • Experience better blood flow from being less constricted than a smaller bed  
  • Less night tumbles for greater quality of sleep 
  • Perfect for all sleep positions

Bonus: An Alternative to the King Bed: The Split King 

A split king bed is perfect for couples where one person is an active sleeper. Meaning they move around a lot in bed. A split king bed is essentially two twin mattresses that work perfectly with an adjustable base. Each person has their own mattress but they are so close together that it feels like you’re sleeping in the same bed. 


Is the California King Bigger Than the King Bed? 

King size bed measurements are 76”x80” and the mattress dimensions of a California king are 72”x84”. So when comparing the king vs. california king, the cal king mattress 4 inches narrower and 4 inches longer than a king size mattress. Both mattresses are essentially the same size but the cal king is proportioned for those of tall stature to sleep comfortably.    

What’s the Largest Mattress Size? 

When shopping for a new mattress you’ve probably seen twin mattress size, twin XL, full, queen, king, and California king. Other mattress sizes include Wyoming size at 84”x84” and Alaska king at 108”x108”. However, a queen size mattress dimensions are better suited to most people because the width of queen bed is just 60”, perfect for most bedrooms.

What’s the Most Popular Mattress Size?

Queen bed dimensions make it the most popular mattress size in America at 60”x80”. When comparing a king vs. queen, the queen provides optimal sleep space for a single or a couple who sleeps close, it’s affordable for as little as $799, and it's easy to find sheets and bedding to fit in many styles and colors.   


Your new bed is an investment in your sleep health, it should provide plenty of sleep space, be pressure relieving, durable, and cooling. The size of twin bed may be best suited to children and young adults, while the width of king bed allows plenty of space for couples with children and pets to enjoy. Full bed size and twin bed size are better suited to young adults and single sleepers. A king size mattress is an affordable and comfortable choice for most people.