Eachnight may earn commissions for products you purchase through our links. Our articles and reviews include affiliate links and advertisements, including amerisleep advertising. Learn more Updated September 21, 2021Looking for a new mattress can be a tricky business—considering room size, measuring the bed frame, and deciding if the mattress is for a master bedroom or guest room. Larger mattresses like king size beds will need extra space, while full mattresses fit perfectly in smaller rooms.In our article, we go over the differences between a king and full size mattress and outline other standard mattress sizes.What’s a King Size Mattress? A king, or eastern king, size mattress measures 76 inches by 80 inches—the largest standard size available. A king bed is equivalent to two twin XL beds placed side by side—a perfect mattress size for couples who want more personal space.King mattresses are also available as a split king option. Couples can enjoy customized comfort and support for better sleep.PricingThe price for a king size mattress ranges between $700 to $4000, depending on the sleep technologies and materials included in the bed.Recommended Room SpaceBecause king mattresses are so large, master bedrooms at least 12 feet by 12 feet are best, providing enough space for furniture and walking area.ProsPerfect for couplesIdeal for master bedroomsSplit king optionConsToo large for some bedroomsExpensiveDifficult to moveWhat’s a Full Size Mattress? A full size mattress is 56 inches by 75 inches. Also known as a “double bed,” full mattresses are an excellent choice for single sleepers—teenagers, college students, and adults with limited living space, like studio apartments. Full size beds have more width than a twin, providing extra space to stretch. Double mattresses are commonly found in college dorm rooms and are also good for guest bedrooms.PricingA full size or double bed costs between $500 to $3000. The price depends on special features and the number of materials inside the mattress.Recommended Room SpaceFull beds are perfect for smaller bedrooms, measuring 10 feet by 12 feet, leaving plenty of room for additional furniture and walking space.ProsExcellent for single sleepersFits small bedroomsBudget-friendlyEasier to moveConsNot enough room for couplesToo short for taller sleepersOther Mattress SizesIf the mattress dimensions of a king or a full aren’t right for the space you have in mind, a twin, twin XL, queen, and California king, might be the best mattress for you.Twin Mattress Twin size mattresses are 38 inches by 75 inches—the smallest mattress size available. Twin beds are perfect for children and compatible with bunk beds, so families with more than one child can utilize space.Twin XL Mattress Twin XL size mattresses measure 38 inches by 80 inches; 5 inches longer than a twin bed. Twin XL mattresses are great for individuals taller than 6 feet and fit nicely in smaller spaces.Queen Mattress Queen size mattresses are 60 inches by 80 inches. Queen beds are a popular mattress size with single adults living on their own, offering plenty of room to sprawl out. They’re also a good option for couples who like to cuddle.California King Mattress California king size mattresses measure 72 inches by 84 inches, the same area as a standard king size, except longer and narrower. California king beds are excellent for taller couples who need more legroom.Though not as widely accessible as a split king, split California king options are also available for couples looking for personalized comfort and support.Other Things to ConsiderHow much bigger is a king than a full?A king size mattress is 20 inches wider and 5 inches longer, an excellent option for couples. King size beds provide 38 inches of personal space and extra length for taller sleepers. Full size mattresses are better for single sleepers.Is a full bed big enough for two?Full beds are only 56 inches wide—that’s 28 inches of wiggle room per person, a whole 10 inches less than what a king mattress offers (38 inches). Full mattresses may be too small for couples, but they’re great for single adults.What size bed do most couples have?Most couples sleep comfortably on a queen, king, or California king size mattress, depending on budget and available space. Other mattress sizes, including twin, twin XL, and full, will feel too small and cramped for two people.Is there a bigger size than king?Yes, there are oversized mattresses that you can custom order. Such variations include:Wyoming king: 84 inches by 84 inchesTexas king: 80 inches by 98 inchesAlaska king: 108 inches by 108 inchesDo two twins equal a king?No, two standard twin beds do not equal a king or any other mattress size. Their length is 5 inches shorter than a standard king. It is two twin XL mattresses that, when pushed together, take up the same amount of space as a king mattress.ConclusionWhether you choose a king or full size bed, the best mattress will accommodate your living space and add to a comfortable atmosphere for better sleep.About the author Andrea Strand CERTIFIED SLEEP COACH Andrea Strand is a Certified Sleep Science Coach. She earned her Bachelor of Arts degree from Brigham Young University-Idaho where she studied English with an emphasis in Technical Writing. Since 2019, Andrea has written over 90 blog posts and guides on sleep health, sleep hygiene, and product reviews. Find more articles by Andrea Comments Cancel replyLeave a CommentYour email address will not be published. Required fields are marked * Comment Name Email I agree to the Terms and Conditions of this website.