Mattress Sizes and Dimensions: The Complete US Size Chart
The six standard US mattress sizes are twin (38 x 75 inches), twin XL (38 x 80), full (54 x 75), queen (60 x 80), king (76 x 80) and California king (72 x 84). A queen is the most common choice for couples, a king gives two people the most width, and a twin XL is the go-to for tall single sleepers and dorm rooms.
Below you'll find a mattress size chart in inches and centimeters, a room planner to check what fits, and a section on each size covering who it suits and how big your bedroom should be. We also cover the less common sizes: split king, Olympic queen and RV mattresses.
One tip before you start: measure your room, doorways and stairwells first. A bed that fits on paper can still feel cramped once nightstands and dressers go in.
On this page
- Mattress size chart: all US dimensions at a glance
- Plan your room: how much space each mattress size needs
- Twin mattress dimensions: 38 x 75 inches
- Twin XL dimensions: 38 x 80 inches
- Full mattress dimensions: 54 x 75 inches
- Queen mattress dimensions: 60 x 80 inches
- Queen vs king mattress measurements
- King mattress dimensions: 76 x 80 inches
- California king dimensions: 72 x 84 inches
- Split king: two twin XLs that make a king
- Olympic queen: 66 x 80 inches
- RV mattress sizes
- Oversized and specialty sizes
- How to choose the right mattress size
- FAQ
Mattress size chart: all US dimensions at a glance
| Size | Inches (W × L) | Centimeters | Best for |
|---|---|---|---|
| Twin | 38″ × 75″ | 97 × 191 cm | Kids, bunk beds, small guest rooms |
| Twin XL | 38″ × 80″ | 97 × 203 cm | Dorms, tall teens, split king halves |
| Full (double) | 54″ × 75″ | 137 × 191 cm | Single adults, guest rooms |
| Queen | 60″ × 80″ | 152 × 203 cm | Most couples, master bedrooms |
| King | 76″ × 80″ | 193 × 203 cm | Couples who want space, kids or pets in bed |
| California king | 72″ × 84″ | 183 × 213 cm | Tall sleepers, longer rooms |
| Split king | 76″ × 80″ | 193 × 203 cm | Two twin XLs — adjustable bases, different firmness |
| Olympic queen | 66″ × 80″ | 168 × 203 cm | Extra 6″ of width (sheets are harder to find) |
Which size fits whom, in one line each:
| Size | Best for |
|---|---|
| Twin | Kids, bunk beds, small guest rooms |
| Twin XL | Tall teens and adults, dorms |
| Full (double) | Single adults who want room to spread out |
| Queen | Most couples and single adults |
| King | Couples who want space, families with pets or kids |
| California king | Tall sleepers, long narrow rooms |
| Split king | Couples with different firmness needs, adjustable bases |
| Olympic queen | Couples who want a little more than a queen |
Mattress thickness isn't part of the size. Height varies by model, from about 8 inches to 14 inches or more among popular online mattresses, so check it against your frame and sheets separately.
Plan your room: how much space each mattress size needs
A good rule of thumb is to leave about 24 to 30 inches of walking space on each side of the bed you need to get around, and at the foot. Add your bed frame, which can add a few inches in each direction, plus nightstands and a dresser.
Will it fit? Room planner
Pick a size and enter your room to see how much walking space you’ll have.
Use the planner above with your actual room measurements. The minimum room sizes below assume a basic layout with walking space; they're a starting point, not a hard rule.
Twin mattress dimensions: 38 x 75 inches
The twin (sometimes called a single) is the smallest standard adult mattress. At 38 inches wide, it gives one sleeper about the same width each partner gets on a king.
Good for: kids moving out of a toddler bed, bunk beds and trundles, daybeds, and small guest rooms.
Watch out for: at 75 inches (6 feet 3 inches) long, a twin is short for most adults and many teens. If someone is close to 6 feet tall, their feet may hang off.
Minimum room size: about 7 x 10 feet, especially if one long side of the bed sits against a wall.
Twin XL dimensions: 38 x 80 inches
The twin XL keeps the twin's width but adds 5 inches of length, matching the length of a queen and king. That makes it the standard for college dorms and a smart pick for tall teens.
Good for: dorm rooms, tall single sleepers, and kids you expect to grow quickly. Two twin XLs side by side also make a split king.
Watch out for: regular twin sheets won't fit. Buy twin XL bedding.
Minimum room size: about 7 x 10 feet, the same as a twin.
Full mattress dimensions: 54 x 75 inches
A full, also called a double, is 16 inches wider than a twin but the same 75 inches long.
Good for: single adults who like to stretch out, teens, and guest rooms that host one person most of the time.
Watch out for: a full is tight for two adults. Each person gets just 27 inches of width. It's also short for anyone over about 6 feet. Some brands sell a full XL (54 x 80) to fix the length, but it's uncommon.
Minimum room size: about 10 x 10 feet.
Queen mattress dimensions: 60 x 80 inches
The queen is the most popular mattress size in the US, and the one brands usually quote prices for. It's 6 inches wider and 5 inches longer than a full.
Good for: most couples, single adults who want generous space, and primary bedrooms in typical homes. Bedding and frames are the easiest to find in this size.
Watch out for: two adults get 30 inches each, which can feel snug if either partner sprawls, or if a pet or child joins at night. Couples who want more room should look at a king.
Minimum room size: about 10 x 10 feet, with 10 x 12 feet more comfortable once you add nightstands.
Queen vs king mattress measurements
The king is 16 inches wider than a queen (76 vs 60 inches) and the same 80 inches long. In practice, a king gives each partner 38 inches, the width of a twin, while a queen gives each 30. If you share a bed and your room is at least about 12 feet wide, the king is usually worth the extra space. If the room is closer to 10 feet, a queen leaves you room to walk around.
King mattress dimensions: 76 x 80 inches
Sometimes called an Eastern king or standard king, this is the widest common size.
Good for: couples who want space, light sleepers who are easily disturbed by a partner, and households where kids or pets often end up in bed. For more on motion and edge support, see our best mattress for couples list.
Watch out for: a king can be hard to move through narrow halls and stairwells, though boxed mattresses solve most delivery problems. Bedding and frames cost more.
Minimum room size: about 12 x 12 feet.
California king dimensions: 72 x 84 inches
The California king is 4 inches longer and 4 inches narrower than a standard king. It isn't "bigger"; it's just shaped differently. A king has more total surface area.
Good for: people over about 6 feet tall, and rooms that are longer than they are wide.
Watch out for: California king sheets and frames aren't interchangeable with a standard king. Make sure you buy the right one.
Minimum room size: about 12 x 12 feet.
Split king: two twin XLs that make a king
A split king is two twin XL mattresses (38 x 80 each) placed side by side to make a 76 x 80 king surface. It's the standard choice for couples using an adjustable base where each side moves on its own.
Good for: partners who need different firmness levels or want to raise their side independently. Adjustable air beds like the Sleep Number c2 solve the same problem a different way, with firmness set separately for each side.
Watch out for: there's a seam down the middle. Fitted sheets are sold either as two twin XL sheets or as split-king sets.
Olympic queen: 66 x 80 inches
The Olympic queen is 6 inches wider than a standard queen. It's a middle ground for couples who want a little more room without the full jump to a king. The catch is that few brands make it, and sheets and frames are harder to find, so most shoppers are better off choosing between a regular queen and a king.
RV mattress sizes
RV and camper mattresses don't follow one standard. Common sizes include the RV short queen, usually around 60 x 74 or 60 x 75 inches, RV kings that are often shorter or narrower than a home king, and narrow bunk mattresses. Always measure the bed platform in your vehicle rather than going by the size name, and check the mattress height too, since RV beds often have limited clearance.
Oversized and specialty sizes
Custom sizes such as Alaskan, Texas and Wyoming kings exist for families that co-sleep or want a statement bed. They need custom frames and bedding, so they're rare and expensive. Crib and toddler mattresses follow their own safety standards and aren't covered here.
How to choose the right mattress size
Ask four questions:
- Who sleeps in the bed? One adult can be comfortable on a full or queen. Two adults usually want a queen or king.
- How tall are you? At 6 feet or taller, skip twin and full and look at twin XL, queen, king or California king.
- How big is the room? Leave room to walk around and open drawers. Use the planner above.
- What's your budget? Each step up in size raises the price of the mattress, frame and bedding.
Once you know your size, the next decision is firmness and type. Our guide to choosing a mattress walks through it step by step, the mattress firmness scale helps you pick a feel, and our quiz matches you to specific mattresses.
If you're buying online, a mattress in a box makes larger sizes easier to get through doors and up stairs. And if the new bed is replacing an old one, our guide on how to dispose of a mattress covers what to do with it.
Frequently asked questions
What are the standard mattress sizes in the US?
There are six standard US sizes: twin (38 x 75 inches), twin XL (38 x 80), full (54 x 75), queen (60 x 80), king (76 x 80) and California king (72 x 84). Split king, which is two twin XLs side by side, is also widely sold. Olympic queen (66 x 80) and RV sizes exist but are less common and harder to find bedding for.
Is a California king bigger than a king?
No. A California king is longer but narrower: 72 x 84 inches versus 76 x 80 for a standard king. That's 4 extra inches of length and 4 fewer inches of width. A standard king actually has slightly more total sleeping surface. Choose a California king if you're tall or your room is long and narrow; choose a king if you want the most width.
What size is a full mattress compared to a queen?
A full is 54 x 75 inches and a queen is 60 x 80 inches, so the queen is 6 inches wider and 5 inches longer. That difference matters most for couples and tall sleepers. A full gives two people only 27 inches each, while a queen gives 30 inches each. For one adult, a full is often enough.
What size room do you need for a king bed?
Plan on a room of at least about 12 x 12 feet for a king. That leaves roughly 2 to 3 feet of walking space around the bed plus room for nightstands. A king can fit in a smaller room, but it will feel crowded and may block closet doors or drawers. Measure your space before ordering.
What size mattress is best for a couple?
A queen is the most popular choice for couples and fits most bedrooms. If you have the space and either partner sprawls, sleeps lightly or shares the bed with a pet or child, a king gives each person 38 inches instead of 30. Couples with very different firmness preferences may prefer a split king.