If you’re wondering how many feet long is a king size bed, a standard U.S. king mattress is 80 inches long, which equals 6 feet 8 inches or approximately 6.67 feet.
A standard king mattress is also 76 inches wide, making its dimensions 76 inches × 80 inches. In feet, that is approximately 6.33 feet wide × 6.67 feet long.
The mattress itself is not the same size as the complete bed frame. A bed frame, headboard, footboard, or platform can add several inches to the overall length and width.
Understanding the exact dimensions is useful when you’re buying a mattress, planning bedroom furniture, checking whether a king bed will fit in a room, or comparing king, queen, California king, and other mattress sizes.
Quick Answer: How Many Feet Long Is a King Size Bed?
A standard U.S. king size mattress is:
- 80 inches long
- 6 feet 8 inches long
- 6.67 feet long
- 203.2 centimeters long
- 2.032 meters long
The standard width is:
- 76 inches
- 6 feet 4 inches
- 6.33 feet wide
- 193 centimeters wide
- 1.93 meters wide
| King Bed Measurement | Size |
|---|---|
| Length | 80 inches |
| Length in feet | 6.67 feet |
| Length in feet & inches | 6 ft 8 in |
| Width | 76 inches |
| Width in feet | 6.33 feet |
| Width in feet & inches | 6 ft 4 in |
| Length in centimeters | 203.2 cm |
| Width in centimeters | 193 cm |
| Mattress area | 6,080 sq. in. |
How Do You Convert 80 Inches to Feet?
The easiest way to convert the length of a king mattress from inches to feet is to divide the number of inches by 12.
There are 12 inches in 1 foot.
So:
80 ÷ 12 = 6.6667 feet
Therefore:
80 inches = 6.67 feet
In feet and inches, the answer is:
6 feet 8 inches
This is often the easiest measurement to use when planning a bedroom because people generally describe furniture dimensions using feet and inches rather than decimal feet.
Why Is a King Bed 6 Feet 8 Inches Long?
The standard U.S. king mattress has a length of 80 inches.
Since:
72 inches = 6 feet
there are 8 inches remaining:
80 − 72 = 8 inches
Therefore:
80 inches = 6 feet 8 inches
So when someone asks how many feet long a king size bed is, the most practical answer is:
A standard king size mattress is 6 feet 8 inches long.
Standard King Bed Dimensions
A standard king mattress measures:
76 inches wide × 80 inches long
Converting both measurements to feet:
76 ÷ 12 = 6.33 feet
80 ÷ 12 = 6.67 feet
Therefore, the mattress is approximately:
6.33 feet wide × 6.67 feet long
Or, using feet and inches:
6 feet 4 inches wide × 6 feet 8 inches long
King Bed Dimensions in Different Units
| Unit | Width | Length |
|---|---|---|
| Inches | 76 in | 80 in |
| Feet | 6.33 ft | 6.67 ft |
| Feet & inches | 6 ft 4 in | 6 ft 8 in |
| Centimeters | 193 cm | 203.2 cm |
| Meters | 1.93 m | 2.032 m |
Is a King Bed 7 Feet Long?
No. A standard king mattress is not 7 feet long.
It is:
6 feet 8 inches long
Since 7 feet equals:
7 × 12 = 84 inches
a 7-foot-long mattress would be 84 inches long.
A standard king is 80 inches, so it is 4 inches shorter than 7 feet.
However, the complete bed frame can sometimes extend beyond the mattress and may approach or exceed 7 feet depending on its design.
How Much Space Does a King Bed Take Up?
The mattress itself covers:
76 × 80 = 6,080 square inches
To convert this to square feet:
6,080 ÷ 144 = 42.22 square feet
Therefore, a standard king mattress occupies approximately:
42.22 square feet
This is the mattress footprint, not the total floor space needed for the bedroom.
You’ll need additional room around the bed for:
- Walking
- Nightstands
- Drawers
- Closets
- Doors
- Other furniture
- Making the bed
A bedroom that technically fits a king mattress may still feel cramped if there isn’t enough clearance around it.
What Size Room Is Best for a King Bed?
A king bed can physically fit in a relatively small room, but a larger bedroom is usually much more comfortable.
A room around 12 × 12 feet can sometimes accommodate a king bed, but furniture placement may be tight.
A 12 × 14-foot room provides more practical space.
A 14 × 14-foot or larger room generally offers greater flexibility for a king bed, nightstands, dressers, and walking space.
The ideal room size depends on the bed frame, furniture arrangement, doors, windows, and how much open floor space you want.
Example: King Bed in a 12 × 12 Room
A 12 × 12-foot room has:
144 square feet
The king mattress occupies approximately:
42.22 square feet
That leaves approximately:
101.78 square feet
for circulation and other furniture, although the usable space depends heavily on the layout.
King Bed vs. Queen Bed Length
A standard king and queen mattress are generally the same length in the United States.
Both are typically:
80 inches long
That’s:
6 feet 8 inches
The main difference is width.
| Mattress Size | Width | Length |
|---|---|---|
| Twin | 38 in | 75 in |
| Twin XL | 38 in | 80 in |
| Full | 54 in | 75 in |
| Queen | 60 in | 80 in |
| King | 76 in | 80 in |
| California King | 72 in | 84 in |
This means a standard king gives you significantly more width than a queen, while both provide the same standard 80-inch length.
King Bed vs. California King
One of the most important comparisons is between a standard king and a California king.
A standard king measures:
76 × 80 inches
A California king measures:
72 × 84 inches
In feet:
Standard King: 6 ft 4 in × 6 ft 8 in
California King: 6 ft × 7 ft
Therefore, a California king is 4 inches narrower but 4 inches longer than a standard king.
Which One Is Longer?
The California king is longer.
- Standard king: 80 inches
- California king: 84 inches
The California king is exactly 7 feet long.
This can make it a better choice for taller sleepers who want additional legroom.
How Long Is a King Bed Frame?
The mattress is typically 80 inches long, but a king bed frame may be longer.
Depending on its construction, a frame can extend beyond the mattress because of:
- Headboard thickness
- Footboard design
- Decorative edges
- Frame rails
- Storage components
- Built-in shelving
For this reason, don’t assume an 80-inch mattress means the complete bed will occupy exactly 80 inches of floor length.
Before buying furniture, check the manufacturer’s overall assembled dimensions.
How Many Feet Long Is a King Bed With a Headboard?
There is no universal length for a king bed with a headboard.
The mattress itself remains approximately:
6 feet 8 inches long
But the headboard adds depth to the overall footprint.
For example, if a headboard extends 4 inches beyond the mattress, the overall length could be approximately:
84 inches = 7 feet
If it extends 8 inches beyond the mattress:
88 inches = 7 feet 4 inches
Therefore, measure the complete bed frame rather than relying only on standard mattress dimensions.
King Bed Dimensions in Meters
A standard king mattress is approximately:
2.032 meters long
and:
1.93 meters wide
For practical measurements, you can round this to approximately:
2.03 meters × 1.93 meters
This conversion can be especially useful when comparing international mattress sizes.
King Bed Dimensions in Centimeters
Since one inch equals 2.54 centimeters:
80 × 2.54 = 203.2 cm
So the standard king mattress is:
203.2 cm long
For the width:
76 × 2.54 = 193.04 cm
So the mattress is approximately:
193 cm wide × 203.2 cm long
How Many Feet Long Is a King Size Bed in the UK?
The term “king size” can refer to different dimensions depending on the country.
This is important because a U.S. king is not necessarily the same size as a UK king.
A standard U.S. king mattress is:
76 × 80 inches
If you’re buying a mattress, bed frame, sheets, or other accessories internationally, always check the manufacturer’s listed dimensions instead of assuming that every king-size product uses the same measurements.
How Many People Can Sleep on a King Bed?
A king bed is designed primarily for two adults and provides substantial sleeping width for each person.
The 76-inch width provides considerably more personal space than a queen mattress.
A king can also be useful for couples who:
- Move around while sleeping
- Share the bed with children occasionally
- Have pets
- Prefer extra personal space
- Want more room for pillows
However, the mattress length remains 80 inches, so exceptionally tall sleepers may prefer a California king or another longer mattress option.
How Much Longer Is a King Bed Than a Twin?
A standard twin mattress is approximately 75 inches long, while a standard king is 80 inches long.
Therefore:
80 − 75 = 5 inches
A king mattress is approximately 5 inches longer than a standard twin.
However, the major difference is width.
A twin is about 38 inches wide, while a king is 76 inches wide.
So a king is approximately twice as wide as a standard twin mattress.
Common Mistakes When Measuring a King Bed
Mistake 1: Confusing Mattress Size With Bed Size
The mattress and complete bed frame can have different dimensions.
Always check the overall dimensions if you’re planning furniture placement.
Mistake 2: Assuming Every King Bed Is Identical
Different countries and manufacturers can use different king-size standards.
Check the actual mattress specifications before purchasing sheets or frames.
Mistake 3: Forgetting the Headboard
A large headboard can add several inches to the total footprint.
Mistake 4: Measuring Only the Mattress
If you’re determining whether the bed will fit in a room, measure the entire assembled frame.
Mistake 5: Ignoring Clearance
A bed may technically fit in a room but still leave insufficient space for walking or opening doors and drawers.
FAQs
How many feet long is a king size bed?
A standard U.S. king size mattress is 80 inches long, which equals 6 feet 8 inches or approximately 6.67 feet.
Is a king bed 7 feet long?
A standard king mattress is not 7 feet long. It is 6 feet 8 inches long. A California king, however, is typically 84 inches long, which equals exactly 7 feet.
How wide is a king size bed in feet?
A standard U.S. king mattress is 76 inches wide, which equals 6 feet 4 inches, or approximately 6.33 feet.
How many feet is an 80-inch mattress?
An 80-inch mattress is 6.67 feet long, or exactly 6 feet 8 inches.
Is a king bed longer than a queen?
In standard U.S. mattress sizes, both king and queen mattresses are typically 80 inches long. The king is wider.
How long is a California king bed?
A standard California king mattress is 84 inches long, which equals 7 feet.
Will a king bed fit in a 12 × 12 room?
A king mattress can fit in a 12 × 12-foot room, but the available walking and furniture space may be limited. The complete bed frame and room layout should be considered before purchasing.
Final Answer: How Many Feet Long Is a King Size Bed?
A standard U.S. king size mattress is 80 inches long.
Converting inches to feet:
80 ÷ 12 = 6.67 feet
So the simplest answer is:
A standard king size bed is 6 feet 8 inches long, or approximately 6.67 feet.
Its standard mattress dimensions are 76 inches wide × 80 inches long, equivalent to approximately 6 feet 4 inches wide × 6 feet 8 inches long.
Remember that the mattress and complete bed frame can have different dimensions. If you’re planning a bedroom or checking whether a king bed will fit, use the manufacturer’s overall bed dimensions and allow additional space for walking and other furniture.
