King Size Bed Dimensions: Inches, Feet, CM and Room Size

Q: What size room do I need for a king bed?

Sources suggest at least 12 by 12 feet, though one says 10 by 14 feet is enough. Leave about 24 inches of walking room on the sides and 36 inches at the foot.

A standard king size mattress is about 76 inches wide and 80 inches long. In feet, that’s roughly 6 feet 4 inches by 6 feet 8 inches. In centimeters, it’s about 193 by 203. It’s the widest standard mattress, and it gives two sleepers plenty of space.

This article is part of our bed sizes chart, where you can compare related options.

Knowing the right numbers helps you pick a frame, sheets and a room layout that work together. It also helps you avoid a common mistake, buying a bed that fits on paper but leaves no room to walk.

This guide gives king size bed dimensions in inches, feet and centimeters. It compares the king to the queen, explains how much room you need, covers frame size and answers common questions about sheets and sizing.

Contemporary bedroom interior with a king-sized bed and elegant decor for a luxurious feel

King Size Bed Dimensions in Inches, Feet and CM

Unit	Width	Length
Inches	76	80
Feet	6 ft 4 in	6 ft 8 in
Centimeters	About 193	About 203

The surface area is about 6,080 square inches. Each of two sleepers gets about 38 inches of width, similar to a twin XL mattress. That’s why a king is also the size of two twin XL mattresses side by side.

Some retailers list a narrower “king” at 72 by 78 inches, which is about 183 by 198 cm. This is common in some countries, including parts of Asia. In the United States, the standard king is 76 by 80 inches. If you’re ordering from another country or an international site, check the size in inches or centimeters, and not just the name.

Mattress thickness is separate. It ranges from about 8 inches to 16 inches or more. Add the height of the frame and foundation to find your final bed height.

King vs Queen: Size Comparison

Size	Width	Length	Surface area
Queen	60 in (152 cm)	80 in (203 cm)	4,800 sq in
King	76 in (193 cm)	80 in (203 cm)	6,080 sq in
California king	72 in (183 cm)	84 in (213 cm)	6,048 sq in

A king is 16 inches wider than a queen, and they’re the same length. That extra width is what couples feel most. A queen gives each person about 30 inches, while a king gives about 38. A California king is narrower than a king but 4 inches longer, which suits tall sleepers.

A king usually costs more, and so do its sheets, frame and bedding. A queen suits smaller rooms and tighter budgets.

How Much Room Do You Need for a King Bed?

One guide recommends a room of at least 12 by 12 feet for a king. Another says a king needs at least 10 by 14 feet. A third suggests a king works best in rooms 13 feet wide or more. For comparison, one source puts the minimum room for a queen at 10 by 10 feet.

You can do the math for your own room. A king is 76 inches wide. If you want about 24 inches of walking space on each side and 36 inches at the foot, you’ll need around 124 inches (about 10 feet 4 inches) of width. For length, 80 inches plus 36 inches is 116 inches (about 9 feet 8 inches). That’s before you add a dresser, nightstands or a closet door. This is a planning estimate, not an official standard.

If your room is exactly 12 by 12 feet, one source says a queen is generally more comfortable to live with day to day. A king in a 12 by 12 room can work, but it will feel full once you add nightstands and a dresser.

Tips to test the fit: Tape the bed outline on the floor and live with it for a day. Check the door swing, closet doors and drawers. Remember that headboards add a few inches in depth. Leave space for nightstands, which add 16 to 24 inches on each side.

King Bed Frame Dimensions

The mattress size is not the frame size. A king frame is larger because of the side rails, headboard and footboard. Expect a king frame to be around 78 to 82 inches wide and 82 to 90 inches long, depending on the style. Platform beds with wide edges or storage drawers may be bigger.

Check the exact size on the product page. A king frame also needs strong support, usually a center rail with legs that reach the floor, to keep the wide mattress from sagging in the middle.

King Sheets, Comforters and Bedding

King sheets are made for a 76 by 80 inch mattress. Queen sheets are too small, and California king sheets are the wrong shape. Always buy bedding that matches your mattress size. Check the pocket depth if you have a thick mattress.

A king comforter or duvet is wider than a queen’s, so it covers the bed with some drape. King pillows, called king-size pillows, are longer than standard pillows, and you can use two on a king bed.

Will a King Bed Fit Through Your Door?

A king mattress is large, but you can still move it. Bed-in-a-box mattresses ship compressed and pass easily through standard doors. Traditional mattresses and box springs are rigid, so they may get stuck on stairs and in narrow halls. Measure all doors, halls, stairs and elevators on the path. A split box spring helps.

Is a King Bed Right for You?

A king is a good choice if you: share the bed with a partner who moves a lot; have kids or pets who join you; like extra room to spread out; have a room that’s at least 12 by 12 feet, or larger.

A queen might be better if your bedroom is small, if you move often or if you want to keep costs down. A California king may be a better pick if you or your partner are tall.

Frequently Asked Questions

What are the dimensions of a king size bed?

A standard US king mattress is 76 inches wide by 80 inches long, which is about 193 by 203 centimeters.

How big is a king bed in feet?

About 6 feet 4 inches wide and 6 feet 8 inches long.

How much wider is a king than a queen?

A king is 16 inches wider than a queen, and they are the same length.

What size room do I need for a king bed?

At least 12 by 12 feet, though one says 10 by 14 feet is enough. Leave about 24 inches of walking room on the sides and 36 inches at the foot.

Is a California king bigger than a king?

It’s about the same total area, but the shape is different. A California king is 72 by 84 inches, narrower and longer than a standard king.

Are king size bed dimensions the same worldwide?

No. Some countries use different sizes. For example, a narrower 72 by 78 inch king is common in some places. Always check the measurements.

Conclusion

A king size bed is about 76 inches wide and 80 inches long, or around 193 by 203 centimeters. It’s 16 inches wider than a queen and gives couples the most space of any standard mattress. The frame, headboard and walking room add to the footprint, so measure carefully.

Plan for at least a 12 by 12 foot room, check the path to the bedroom and buy sheets that match the mattress size. With the right numbers, a king bed can be a comfortable and roomy choice.