Mattress Size Chart: Twin to King, Explained

A queen mattress measures 60 by 80 inches; a king is 76 by 80 — sixteen inches wider, identical in length. Those two sizes anchor the US standard lineup, which runs from the 38-inch-wide twin to the extra-long California king. The chart below covers all six, plus the minimum room size each one needs to live comfortably.

The Complete US Mattress Size Chart

Size	Dimensions (W x L)	Best for	Minimum room size
Twin	38 x 75 in.	Kids, bunk beds, daybeds	7 x 10 ft
Twin XL	38 x 80 in.	Taller solo sleepers, dorms, split kings	8 x 10 ft
Full (Double)	54 x 75 in.	Single adults, guest rooms	10 x 10 ft
Queen	60 x 80 in.	Couples, primary bedrooms, guest rooms	10 x 10 ft
King	76 x 80 in.	Couples who want space; kids and pets in the bed	12 x 12 ft
California King	72 x 84 in.	Sleepers over 6 ft; long, narrow rooms	12 x 12 ft

Minimum room sizes assume the essentials: walkways on the open sides and space for nightstands. The math behind them is below.

Each Size, in Practice

Twin and Twin XL — 38 inches wide

The twin (38 x 75) is the children's-room and bunk-bed standard. The twin XL adds 5 inches of length — at 38 x 80 it fits sleepers up to about 6'5", which is why college dorms use it almost exclusively. Worth knowing: two twin XLs side by side equal a king (76 x 80) exactly, which is how split kings work for couples with different firmness needs.

Full — 54 inches wide

The full (also called a double) gives a solo adult generous room to sprawl. For couples it's tighter than it sounds: 27 inches per person, which is less width than a crib mattress. Treat it as a one-person bed that can host two occasionally — well suited to guest rooms and smaller city bedrooms.

Queen — 60 inches wide

The most popular size in American homes, and the default for couples. At 60 x 80 it fits two adults at 30 inches each, handles rooms as small as 10 x 10 feet, and keeps the widest selection of frames, sheets, and headboards available. If you're unsure, the queen is the safe answer.

King — 76 inches wide

A king gives each partner 38 inches — exactly a twin apiece. It's the right call for couples who share the bed with children or pets, or for anyone whose partner's movement wakes them. The cost is floor space: plan on a 12 x 12 foot room so the bed doesn't swallow the walkways.

California King — 72 inches wide, 84 inches long

Four inches narrower than a standard king but four inches longer, the Cal king is built for tall sleepers — anyone over about 6'4" whose feet hang off an 80-inch mattress. It also suits long, narrow bedrooms. Note that it is not "bigger than a king"; it trades width for length.

Queen vs. King: The 16-Inch Question

The full comparison in one paragraph: both are 80 inches long, so the difference is purely width — 60 versus 76 inches. On a queen, two adults get 30 inches each; on a king, 38 each, the same personal space as sleeping alone on a twin. The deciding factor is usually the room, not the sleepers. A king with two nightstands needs roughly 10 feet of wall; in a 10 x 10 room it leaves walkways too tight to use, while a 12 x 12 room absorbs it easily. If your room is 11 feet wide or more on the bed wall, the king upgrade is the one couples most rarely regret.

Full vs. Queen: Worth the Step Up?

The queen is 6 inches wider and 5 inches longer than a full. For a single sleeper, a full is comfortable and frees up floor space in a small room. For a couple, the difference is decisive — 27 inches per person on a full versus 30 on a queen, plus length that matters for anyone near six feet. Since both fit a 10 x 10 foot room, couples should default to the queen; choose the full only when the room or the budget genuinely demands it.

Will It Fit? The Room-Size Math

A bed needs breathing room: allow 24 to 30 inches of walkway on each open side and at the foot. A worked example for a queen in a 10 x 10 foot room (120 x 120 inches):

• Width: 60-inch mattress + 30-inch walkways on both sides = 120 inches. Exact fit — or place one side near a wall and gain a generous single walkway.
• Length: 80-inch mattress + 30 inches at the foot = 110 inches, leaving 10 for a dresser wall. Snug, workable.

Two more planning notes. A bed frame adds 2 to 5 inches to each dimension beyond the mattress — more for sleigh beds, wingback headboards, and storage frames, so measure the frame, not the mattress. And if a rug goes under the bed, size it to extend 18 to 24 inches past each side: an 8x10 under a queen, a 9x12 under a king.

The Short Version

Six standard sizes: twin (38x75), twin XL (38x80), full (54x75), queen (60x80), king (76x80), and California king (72x84). Solo sleepers are happy on a full or twin XL; couples start at queen and move to king when the room is 12 x 12 feet or close to it. Plan 24 to 30 inches of walkway around the bed, remember the frame adds a few inches in every direction, and let the room — not ambition — pick the size. For firmness, type, and what to check before you order, continue with our mattress buying guide.

Settled on a size? Shop Mattresses — then find the frame to match in our bedroom collection.