Bed & Mattress Size Chart: Dimensions, Room Sizes & Bedding Fit

Mattress size names sound standard, but they aren't as standard as people assume. A "full" is not the same as a "double XL." A California king is narrower than a regular king. A "queen" sleeper sofa mattress is several inches shorter than a queen bed. And the mattress size tells you nothing about how much floor the finished bed takes up once you add the frame, the headboard and room to walk around it.

This page collects the numbers we look up for customers every week: standard mattress dimensions, how much space each size needs per sleeper, the minimum room size that works for each bed, and how big the finished bed really is. Use it with our mattress buying guide for choosing the mattress itself, and the Will It Fit? measuring guide for getting it into the house.

Standard US Mattress Size Chart

These are the nominal dimensions used by US mattress makers. Real mattresses commonly run up to about an inch smaller in width and length than the listed size, which is normal and is why fitted sheets have a little stretch.

Here's a number that surprises people: two adults sharing a full each get 27 inches of width, which is an inch less than a crib mattress. That's why a full feels crowded for most couples and the queen became the default.

King vs. California King: Which Is Bigger?

Neither, really. They have nearly the same surface area: a king is 6,080 square inches and a California king is 6,048. The difference is shape. A standard king is four inches wider; a California king is four inches longer.

• Choose a king if you share the bed with a partner, a child who climbs in at 3 a.m. or a large dog. Width is what couples run out of.
• Choose a California king if either sleeper is over about 6'2", or if the room is long and narrow and a 76-inch-wide bed would crowd the nightstands.
• Check the bedding first. California king sheets, mattress protectors and bed frames are less common in stores than king. They aren't hard to find online, but you can't borrow a king set in a pinch.
• Two twin XLs make a king, not a California king. That's how a split king works, and it matters if you're considering an adjustable base.

Minimum Room Size for Each Bed

The mattress is only part of the story. For a bedroom that actually works day to day, plan for about 30 inches of clear walkway on each side of the bed you walk around and at the foot, and at least 24 inches as an absolute minimum in a tight room. Then add space for nightstands (usually 18 to 28 inches wide) and the dresser, plus the swing of the closet and entry doors.

In Southeast Michigan, a lot of the houses we deliver to are post-war ranches and bungalows where secondary bedrooms are around 10 by 10 or 10 by 11 feet, and the primary bedroom is often 11 by 12 or 12 by 13. A king fits in many of those primary bedrooms, but often with a single dresser and small nightstands. If you're unsure, mark the bed's outside dimensions on the floor with painter's tape and walk around it. Our bedroom furniture guide covers layout in more depth.

How Big Is the Finished Bed?

Bed frames add to the mattress size, sometimes a lot. Before you decide a king will fit, check the overall dimensions of the frame you actually plan to buy.

A queen sleigh bed can easily be 66 inches wide and 94 inches long, which is the length of a standard king mattress plus more than a foot. Storage beds also need about 18 to 20 inches of clear floor next to them for the drawers to open fully, so check that against your nightstand and walkway.

Bed Height: Mattress, Foundation and Frame

The top of most adult mattresses sits somewhere between 20 and 30 inches off the floor once it's on a frame. A comfortable height is one where you can sit on the edge with your feet flat on the floor and your knees close to level with your hips, roughly 24 to 25 inches for many adults, lower for shorter sleepers.

• Mattress thickness runs from about 8 inches (budget foam, bunk beds) to 14 inches or more for pillow-top hybrids.
• A standard foundation or box spring is about 9 inches; a low-profile one is about 5 inches. Choosing low-profile is the easiest fix for a bed that's too tall.
• Platform beds skip the foundation, so a 12-inch mattress on a platform can end up lower than an 8-inch mattress on a box spring and metal frame.
• Higher isn't always better for older sleepers. A bed that's too tall is a fall risk; too low is hard to stand up from. Have the person who'll sleep there sit on the edge before you buy.
• Bunk beds are the exception. Top bunk mattresses must stay below the guardrail's height limit, which usually means 6 to 8 inches. Our bunk bed guide explains why.

Getting Sheets and Bedding to Fit

Most sheet problems come from mattress depth, not size. A fitted sheet labeled for a queen will cover the width and length of a queen, but only fit a mattress up to a certain thickness.

• Measure thickness with the topper and protector on. A 3-inch topper on a 12-inch mattress needs a deep-pocket sheet.
• Twin and twin XL sheets aren't interchangeable. Twin XL fitted sheets will be baggy on a twin; twin sheets won't stretch over a twin XL.
• Split king uses two twin XL fitted sheets and one king flat sheet, or a split-top king set. A regular king fitted sheet doesn't work if the two halves move separately.
• Comforters and duvets are usually sold as "full/queen" and "king/California king." A full/queen comforter is generous on a full and just right on a queen with a low profile; on a thick pillow-top queen, consider going up a size.

Non-Standard Sizes You'll Run Into

• RV and camper mattresses often run shorter than standard. An "RV queen" is commonly 60 × 74 and a "short queen" may be listed around 60 × 75. Measure the platform, not the label.
• Sleeper sofa mattresses are smaller and thinner than bed mattresses. A "queen" sleeper mattress is commonly about 60 × 72 and around 4.5 to 5 inches thick. Our sleeper sofa guide has the real dimensions by size.
• Antique and older beds sometimes have side rails sized for a "three-quarter" mattress (about 48 × 75) or an older full that's shorter than today's. Measure inside the rails before you buy a new mattress for an heirloom bed.
• Daybeds and trundles take twin mattresses, but the trundle usually needs a thinner one, typically 6 to 8 inches, to slide under the main bed.
• Olympic queen, Alaskan king and Texas king exist but are specialty sizes with limited frame and bedding options. We rarely recommend them unless you have a specific reason.

Will a King Mattress Fit Through Your Door?

Mattresses flex, so they usually go through doorways and up stairs more easily than a box spring or a headboard. Problems we see on delivery:

• Standard king box springs are 76 × 80 and rigid. They don't bend around a tight stair turn, which is exactly why split box springs (two 38 × 80 pieces) exist. If your stairs turn, order split.
• Queen box springs (60 × 80) can be stuck at a low-ceiling basement stair or a narrow upstairs landing in an older colonial or Cape Cod. Split queen foundations are available too.
• Hybrid and innerspring kings are heavy, often 100 to 150 pounds, and floppy. Two people is the minimum to carry one up stairs safely.
• Bed-in-a-box mattresses arrive compressed and are the easiest option for tight stairs, but they still weigh the same once unrolled, so open them in the room where they'll live.

Choosing the Right Size: Quick Recommendations

• One adult, small room: full, or a queen if the room is at least 10 × 10.
• Couple, average bedroom: queen. It's the most common size for a reason, and bedding is everywhere.
• Couple with kids or pets in the bed, or light sleepers: king, if the room allows it.
• Either partner over about 6'2": California king, or a king if width matters more.
• Partners who want different firmness or an adjustable base: split king.
• Growing kids: twin, or twin XL if they're headed for a dorm with twin XL beds later.
• Guest room used a few nights a year: full or queen, or a daybed with a trundle if the room doubles as an office.

Frequently Asked Questions