Rug Size for Room Calculator
A rug that is too small makes a room feel disjointed, while one sized to the space anchors the furniture and ties the layout together. The common design guideline is to leave an even strip of bare floor around the rug on all sides, so the rug fills the room without crowding the walls. This rug size calculator takes your room length and width in feet and the border you want to leave on each side, then returns the recommended rug length, width and total area. A border of about 12 to 18 inches works well in most rooms, leaving a balanced frame of flooring around the rug. In open-plan spaces you might leave a larger border, and in small rooms a smaller one. Every figure here is computed deterministically from your room dimensions and chosen border, so the same room always returns the same rug size. Enter your measurements below to choose a rug that fits before you shop, compare borders, or check that a rug you already own suits the room, with a worked example that reconciles exactly to the calculator defaults so you can confirm each step before you buy or commit to a layout.
Recommended rug size leaves an even border on every side: rug length = room length minus twice the border, and the same for width. A 12 ft by 10 ft room with an 18 in (1.5 ft) border suits a 9.00 ft by 7.00 ft rug, about 63.00 sq ft.
Rug size formula
rug length = room length - (2 x border)
rug width = room width - (2 x border)
rug area = rug length x rug width
border = bare floor left on each side, in feet
Subtracting twice the border from each room dimension leaves an equal strip of floor on every side. Multiplying the resulting rug length and width gives the rug area in square feet.
Worked example
Take a room 12 feet long and 10 feet wide, leaving an 18 inch (1.5 foot) border of bare floor on each side.
- Rug length: 12 - (2 x 1.5) = 12 - 3 = 9.00 ft
- Rug width: 10 - (2 x 1.5) = 10 - 3 = 7.00 ft
- Rug area: 9.00 x 7.00 = 63.00 sq ft
The recommended rug is 9.00 ft by 7.00 ft, about 63.00 square feet, which matches the calculator's default inputs exactly.
Rug Size for Room Calculator: frequently asked questions
How much floor should I leave around a rug?
A border of about 12 to 18 inches of bare floor on each side is a widely used guideline, framing the rug evenly within the room. Larger rooms can carry a wider border and small rooms a narrower one, so this calculator leaves the border as an editable input.
Should all the furniture sit on the rug?
That depends on the room. In a living room you might place only the front legs of large furniture on the rug, while in a dining room the rug should be large enough for chairs to stay on it when pulled out. Adjust the border to suit the layout you want.
What if my room is not rectangular?
For an L-shaped or irregular room, measure the main rectangular area you want the rug to define and use those dimensions. You can run the calculator separately for distinct zones, such as a seating area and a dining area, in an open-plan space.
Does the calculator use feet or inches?
Enter room dimensions and the border in feet. To use an inch measurement for the border, convert it first: 12 inches is 1 foot, 18 inches is 1.5 feet, and 6 inches is 0.5 feet.
Can I size a rug for a specific furniture grouping?
Yes. Instead of the whole room, measure the footprint of the furniture grouping you want the rug to sit under, add the overhang you want beyond the furniture, and use those numbers as your room dimensions with a zero or small border.
Official sources
- Measurement, units and dimensional standards: US National Institute of Standards and Technology (NIST). As at 25 June 2026.
Reviewed by the CalculatorHub team, edited by James Graham, 25 June 2026. See our methodology. This is general information, not financial, tax, legal or investment advice.