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King Size Bed Dimensions

A standard king size mattress is 76 inches wide and 80 inches long (6 ft 4 in x 6 ft 8 in, or 193 x 203 cm). It is 16 inches wider than a queen and the same length. A California king is narrower and longer at 72 x 84 inches.

Will this bed fit my room?

Bed sizeFrame adds (inches, 0 for none)Room width, headboard wall (ft)Room length (ft)

Space each side

32"

Space at foot

72"

Good: 30" or more around the bed, the recommended walkway.

King bed size compared

Mattress sizes. Frames add about 2 to 8 inches; a king headboard is about 79 to 81 inches wide.
Bed	Inches	Centimeters	Feet
King (Eastern king)	76 x 80	193 x 203	6'4" x 6'8"
California king	72 x 84	183 x 213	6' x 7'
Split king	2 x (38 x 80)	2 x (97 x 203)	two twin XL
Queen	60 x 80	152 x 203	5' x 6'8"
Full / double	54 x 75	137 x 191	4'6" x 6'3"
Twin XL	38 x 80	97 x 203	3'2" x 6'8"

King vs California king: which one?

Pick a standard king for couples who want the most width. It is 4 inches wider than a California king.
Pick a California king if you are over about 6 ft tall, or the room is long and narrow. It is 4 inches longer.
Both have almost the same surface area: 6,080 sq in for a king and 6,048 sq in for a California king.
Sheets do not swap. King sheets are too short for a California king, and California king sheets are too narrow for a king.

What room size do you need for a king bed?

Plan for 30 inches of clear floor on each side of the bed and at the foot, and 36 inches for a comfortable room. 24 inches is the least that works in a tight room. Most guides give 12 x 12 ft as the minimum room for a king, and 13 x 13 ft or more as comfortable. With a 76 inch wide mattress:

Room size	Result with a king bed
10 x 12 ft	Fits with about 22" on each side (about 20" with a frame). No room for nightstands.
12 x 12 ft	The usual minimum: 34" on each side, 64" at the foot. Room for small nightstands.
13 x 13 ft and up	Comfortable, with room for nightstands and a dresser.
14 x 16 ft	Primary suite size: bed, nightstands, dresser and a chair.

Doors and closets need their own swing space, so draw the room before you buy. The room-fit tool above shows the clearance for any room size.

King bedding sizes

Item	Typical size
Fitted sheet	76 x 80 in, pocket depth 12 to 18 in
Flat sheet	about 108 x 102 in
Duvet / comforter	about 104-110 x 88-96 in
King pillow	20 x 36 in

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Frequently asked questions

What are the dimensions of a king size bed?

A standard king mattress is 76 inches wide by 80 inches long (193 x 203 cm). With a frame, the bed is usually 78 to 84 inches wide and 82 to 88 inches long.

How much bigger is a king than a queen?

A king is 16 inches wider than a queen (76 vs 60 inches) and the same 80 inch length. It gives each sleeper 38 inches, about the width of a twin bed.

Is a California king bigger than a king?

Not overall. A California king is 4 inches longer (84 inches) but 4 inches narrower (72 inches). The total area is almost the same.

Will a king bed fit in a 10x12 room?

It fits, with about 22 inches on each side for the mattress alone (about 20 with a frame) and no room for nightstands. Most guides give 12 x 12 ft as the minimum for a king, and 13 x 13 ft as comfortable.

What is a split king?

A split king is two twin XL mattresses (38 x 80 inches each) side by side. Together they are the same size as a king, and are used with adjustable bases so each side can move on its own.

More free tools for architects and designers

Sources: Standard US mattress sizes as published by mattress makers. Clearances follow common interior design guidance (30 inch walkway, 36 inch comfortable, 24 inch in tight rooms).