Rug Size for a King Bed
Set how much rug you want beside and past the bed, and pick whether it goes under the whole bed or the lower two-thirds. You get the standard rug sizes that work and the margin each one leaves.
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This rug size for king bed calculator shows which standard rug sizes give you the space you want around a king bed. You enter the bed width and length, how far the rug should reach past each side and the foot of the bed, and where the rug goes. The page then returns the standard rug sizes that give those gaps.
It runs in your browser, is free, and needs no sign-up. Nothing you enter is uploaded. The starting values use a US king mattress, 76 x 80 in, but mattress sizes vary by maker, so check the dimensions of your own bed and the rug you plan to use.
How to use the Rug Size for King Bed Calculator
- Enter the bed width and length in the bed fields. The starting values are 76 x 80 in, a US king mattress. You can use in, ft, cm or m.
- If your bed has a frame or headboard, measure that instead. A frame or headboard makes the bed bigger than the mattress. One guide says headboards add 4-8 in and footboards or benches 10-20 in.
- Choose the rug placement: under the whole bed, or under the lower two-thirds of the bed.
- Open “More options” and set “Rug beyond each side” (18 in to start), “Rug past the foot” (24 in to start), and “Head of the bed is against a wall” (yes to start).
- Read “Rug sizes that work”, which lists each standard size that gives your gaps, and “Smallest rug for these gaps”, which gives the exact width x length in feet, inches and cm.
- Read the table. It lists each size tested, from 5 x 7 ft to 10 x 14 ft. For each size it shows the inches of rug beyond each side and past the foot, the direction the rug lies, and whether the row says “Works” or “Gaps smaller than asked”.
- If a row says “Gaps smaller than asked”, try a larger size.
Warnings appear if a side gap is under 18 in, if the bed is outside 30-100 in wide or 60-100 in long, or if no standard size gives your gaps.
What rug size works for a king bed?
The rule is simple arithmetic. The rug width you want equals the bed width plus twice the side gap. For a king bed with an 18 in gap on each side, that is 76 + 2 x 18 = 112 in. The rug length you want equals the bed length plus the gap past the foot. With the whole bed covered and a 24 in foot gap, that is 80 + 24 = 104 in. A rug of at least 112 x 104 in therefore gives those gaps. A 9 x 12 ft rug, turned so the long side crosses the bed, works: it leaves 34 in on each side and 28 in at the foot.
When the rug covers only the lower two-thirds of the bed, the length counts two-thirds of the bed length plus the foot gap. Two-thirds of 80 in is about 53.3 in, so the rug needs about 77.3 in of length. The width stays 112 in. The smallest rug needed on the starting values is 9 ft 4 in wide x 6 ft 5.3 in long. An 8 x 10 ft rug turned gives 22 in at each side and 42.7 in past the foot, which also works. The tool tries the turned direction first for this placement, because one guide places the rug perpendicular to the bed.
How far should a rug extend past a king bed?
The gap beside and past the bed is a rule of thumb, and the guides differ. The sources the page draws on give 18-24 in or more beside the bed, at least 18 in, or 24-30 in with 18 in as the minimum. For the foot, they give about 24 in, or 24-30 in. The page starts at 18 in for the sides and 24 in for the foot, which are the low ends of those ranges. You can raise or lower them under “More options”.
Direction changes the result. With the short side across the bed, a 9 x 12 ft rug leaves (108 - 76) / 2 = 16 in at each side, and an 8 x 10 ft rug leaves 10 in. Both are below the 18 in starting gap, so the table marks them. One source’s own table lists a 9 x 12 ft rug at 16 in per side while asking for 18 in, and the page shows the 16 in and flags it as below your gap.
Finally, the bed dimensions themselves vary. Mattress sizes differ by about an inch between makers, and a frame or headboard adds to the width, so measure the bed you actually have.
Sources (checked 15 October 2026): atlantadesignerrugs.com · tumbleliving.com · chairish.com · bassettfurniture.com · amerisleep.com · atlantadesignerrugs.com
Worked examples
| Input | Result |
|---|---|
| 76 × 80 in bed, 18 in at the sides, 24 in at the foot, Under the lower two-thirds | works: 8 × 10 ft, 9 × 12 ft, 10 × 14 ft |
| 76 × 80 in bed, 18 in at the sides, 24 in at the foot, Under the whole bed | works: 9 × 12 ft, 10 × 14 ft |
| 76 × 80 in bed, 24 in at the sides, 30 in at the foot, Under the lower two-thirds | works: 9 × 12 ft, 10 × 14 ft |
| 76 × 79.9 in bed, 18.1 in at the sides, 24 in at the foot, Under the lower two-thirds | works: 8 × 10 ft, 9 × 12 ft, 10 × 14 ft |
Calculated by the tool above; open it with the same values to see each step.
Frequently asked questions
What rug size goes under a king bed?
The page starts from a 76 x 80 in king mattress and 18 in at each side, 24 in past the foot. For those gaps the smallest rug is 9 ft 4 in x 6 ft 5.3 in under the lower two-thirds, or 112 x 104 in under the whole bed. Your own bed and gap settings may produce a different size.
Should the rug go under the whole bed or only the lower two-thirds?
Under the whole bed needs a larger rug, because it covers the full bed length. Under the lower two-thirds placement, the rug covers the foot area and the lower part of the bed, so it can be shorter. Choose the placement that fits how you use the room.
How much rug should show on each side of a king bed?
The starting value is 18 in on each side, which is the low end of the gaps the guides give. Some sources suggest 24 in or more. Use the “More options” setting to change this and see which standard sizes still work.
How far past the foot of a king bed should the rug reach?
The starting value is 24 in past the foot. Sources give about 24 in, or 24-30 in. Enter a different value under “More options” and check the table.
Does a king bed frame or headboard change the rug size?
Yes. A frame or headboard is wider than the mattress, and a footboard or bench adds length. Measure the frame and enter those dimensions as the bed width and length. Then the rug widths and lengths in the table match what you see.
Why does a row say “Gaps smaller than asked”?
That row’s rug is smaller than the width or length needed for your gap settings, so it leaves less beside or past the bed than you asked for. For a rug narrower than the bed the table can even show a negative number. Pick a larger size from the table, or lower your gap if your room calls for it.
Related tools
- Bedroom Area Rug Size: Use it when you are choosing a rug for a whole bedroom rather than only the space under the bed.
- Living Room Rug Size: Use it when you are sizing a rug for a sofa and seating area.
- Rug Size Chart: Use it when you want to compare common standard rug sizes at a glance.
- Rug Size for a Dining Table: Use it when the rug goes under a table and chairs.
- Rug Size for a Queen Bed: Use it when your bed is a queen rather than a king.