Mattress and Bed Size Chart: US Dimensions in Inches and cm

US mattress sizes are standard, so a queen from any brand measures the same: 60 × 80 inches. What varies is the thickness, from about 8 to more than 14 inches, which matters for sheets but not for the bed frame. Here’s every size, to the inch and centimeter.

US mattress size chart

Size	Inches (W × L)	Centimeters	Best for
Twin (single)	38 × 75	97 × 191	Kids, bunk beds, daybeds
Twin XL	38 × 80	97 × 203	Tall teens, college dorms
Full (double)	54 × 75	137 × 191	One adult, guest rooms
Queen	60 × 80	152 × 203	Couples, most master bedrooms
King	76 × 80	193 × 203	Couples who want space, kids or pets in bed
California king	72 × 84	183 × 213	Tall sleepers, long narrow rooms
Split king	2 × (38 × 80)	2 × (97 × 203)	Adjustable bases, different firmness each side
Crib	27¼ × 51⅝ (minimum)	69 × 131	Babies and toddler beds

Mattresses can be up to about ½ inch smaller than these numbers, because foam and covers vary. Measure the frame, not the label, if a fit is tight.

How the sizes compare

• Full vs queen: a queen is 6 inches wider and 5 inches longer. Two adults on a full each get 27 inches of width, less than a crib mattress.
• Queen vs king: a king is 16 inches wider, at the same 80 inch length.
• King vs California king: the Cal king trades 4 inches of width for 4 inches of length. A king has more total surface (6,080 vs 6,048 square inches), so pick the Cal king only if you need the length.
• Twin vs twin XL: same width, but the XL is 5 inches longer, enough for most adults.

A useful rule: an adult sleeper should have a mattress at least 6 inches longer than their height. At 80 inches, a queen or king fits people up to about 6 feet 2 inches (188 cm) comfortably; taller sleepers are better on a California king or twin XL.

How much room each bed needs

Leave at least 24 inches (60 cm) of clear floor on the sides you walk around, and 30 to 36 inches if you can. That gives these minimum rooms:

Bed	Minimum room
Twin	7 × 10 ft (2.1 × 3.0 m)
Full	10 × 10 ft (3.0 × 3.0 m)
Queen	10 × 10 ft (3.0 × 3.0 m)
King / California king	12 × 12 ft (3.7 × 3.7 m)

Remember the frame and headboard add to the mattress size: a queen bed frame is often 62 to 65 inches wide and 84 to 90 inches long. To check the room’s square footage, use the square footage calculator.

Crib mattress size and safety

A full-size crib mattress must be at least 27¼ × 51⅝ inches and no more than 6 inches thick, under the US federal safety standard for crib mattresses. The fit matters for safety: if you can fit more than two fingers between the mattress and the side of the crib, the gap is too big and the mattress should be replaced. Mini cribs have no standard size, so buy the mattress made for that crib.

How to measure a mattress or bed frame

1. Width: measure across the top of the mattress from edge to edge, at the middle, not at the corners, which can be rounded.
2. Length: measure from the head to the foot down the center.
3. Depth: measure the side from the bottom seam to the top, including any pillow top. Buy fitted sheets with a pocket at least 1 to 2 inches deeper than this.
4. Frame: measure the inside of the frame where the mattress sits. It should be the mattress size plus about ½ to 1 inch.

A tape measure is the easiest tool; to convert your numbers, use inches to cm or feet to cm.