Understanding your result
The headline is the recommended standard rug size, with the minimum the furniture needs and the maximum the room allows beneath it. The table gives the rule, both limits, the recommendation, every standard size that fits the room, and every standard size big enough for the furniture.
The minimum for the furniture comes from the rule for the arrangement. For a sofa group with front legs on the rug, the rug is at least the sofa length plus 6 in at each end, and deep enough to reach under the front legs of the sofa and the facing chairs. With every leg on the rug, it is the sofa plus 12 in each end and the full depth of the group plus a foot. For a dining table, 24 in beyond the table on every side. For a bed, about 21 in beyond each side and two-thirds of the bed’s length plus 18 in at the foot.
The maximum for the room is the room less the bare floor you want at the walls. The recommended size is the smallest standard size between the two. If none is, the note says why and what to change. For wall-to-wall carpet instead of a rug, use the carpet calculator; to measure an irregular room first, the floor area calculator; for a play area of foam tiles, the foam play mat calculator.
How we calculate this
These are the rules of thumb designers and rug sellers publish, not standards; they differ by a few inches between sources, and the calculator uses the commonly quoted figures. The seating depth is measured from the front of the sofa to the front of the facing chairs, plus the depth of a seat, which is what makes the front-legs rule work. The guide to rug size rules explains each with diagrams and covers hallways and runners, and the guide to measuring odd rooms helps where the room is not a rectangle.
The assumptions behind the numbers
| Assumption | Default | Where it comes from |
|---|---|---|
| Sofa | 84 in (213 cm) | A standard three-seat sofa |
| Seating depth | 8 ft | A typical sofa-to-chairs group with a coffee table |
| Dining clearance | 24 in each side | Common rug-seller guidance for pulled-out chairs |
| Bed overhang | about 21 in each side | Common designers’ guidance (18 to 24 in) |
| Bare floor at the walls | 18 in | Common designers’ guidance (12 to 18 in) |
| Standard sizes | 3 × 5 to 12 × 15 ft; 120 × 170 to 300 × 400 cm | Standard rug sizes sold in the US and Europe |
Assumptions last reviewed October 8, 2026.
The calculator handles one rug for one furniture group in a rectangular room. Open-plan spaces with several groups need one rug per group, each sized by its own furniture. It does not handle round rugs, hall runners or rugs over carpet, and it does not judge style; a rug one size bigger than the minimum is rarely a mistake.
Two worked examples
A 16 × 13 ft living room, front legs on the rug
84 in sofa, 8 ft seating group, 18 in of floor at the walls.
- Minimum: 7 + 1 = 8 ft long; 8 − 1.5 = 6.5 ft deep
- Room limit: (13 − 3) × (16 − 3) = 10 × 13 ft
- Standard sizes meeting the minimum: 8 × 10, 9 × 12 and larger; fitting the room: up to 9 × 12
- Recommended: 8 × 10 ft
A 9 × 12 also fits and would let more furniture sit on the rug. The 5 × 8 that many people buy for a room like this is the floating-rug mistake the rule exists to prevent.
A 13 × 11 ft dining room with a 7 × 3.5 ft table
18 in of floor at the walls.
- Minimum: (7 + 4) × (3.5 + 4) = 11 × 7.5 ft
- Room limit: (11 − 3) × (13 − 3) = 8 × 10 ft
- No standard size meets both: custom size
An 11 ft rug cannot fit a 10 ft space. The options: reduce the border to 12 in (room limit 9 × 11 ft, still short), accept a 8 × 10 with the chairs partly off the rug, or have a 7.5 × 11 ft rug cut from broadloom, which the carpet calculator can price.
Where to find your inputs
Room. Wall to wall at floor level.
Sofa. Overall length including the arms.
Seating depth. From the back of the sofa’s seat front to the back of the facing chairs’ front legs; or measure front of sofa to front of chairs and add about 3 ft.
Table. Length and width with any leaves you use regularly.
Bare floor. How much floor you want to see at the walls: 18 in in most rooms, 12 in in small ones.
Common mistakes
- A rug too small for the furniture. It floats. Go one size up.
- Dining chairs falling off the edge. Add 24 in on every side of the table.
- Wall to wall by accident. Leave 12 to 18 in of floor showing.
- Measuring without the arms. Sofa length includes the arms.
- One rug for an open plan. Each furniture group needs its own.
- Forgetting the rug pad. It should be about 1 in smaller than the rug on every side.
Questions people ask
- What size rug goes under a sofa?
- For the front-legs rule, the rug should extend at least 6 inches past each end of the sofa and reach far enough that the front legs of the sofa and chairs sit on it. With a standard 84 inch sofa and an 8 ft seating group, that is at least 8 ft by 6.5 ft, so an 8 × 10 ft rug.
- What size rug for a dining table?
- Add 24 inches on every side of the table so chairs stay on the rug when pulled out. A 6 × 3.3 ft table needs a rug at least 10 × 7.3 ft, which is an 8 × 10 ft rug; a 7 ft table needs 11 ft, so a 9 × 12.
- What size rug goes under a queen or king bed?
- The rug usually runs crosswise under the lower two-thirds of the bed, extending 18 to 24 inches beyond each side. That is an 8 × 10 ft rug for a queen or king in most rooms, or a 6 × 9 ft for a queen in a small room.
- How much floor should show around a rug?
- Designers usually leave 12 to 18 inches of bare floor between the rug and the walls, so the rug defines the space without looking like wall-to-wall carpet. In a small room 8 to 12 inches is acceptable.
- What are the standard rug sizes?
- In the US, 3 × 5, 4 × 6, 5 × 8, 6 × 9, 8 × 10, 9 × 12, 10 × 14 and 12 × 15 feet. Metric sizes are commonly 120 × 170, 160 × 230, 200 × 290, 240 × 340 and 300 × 400 cm.
- What if no standard size fits?
- Choose the front-legs rule instead of all legs, reduce the floor showing at the walls to 12 inches, or have a rug cut and bound from broadloom carpet to any size. The carpet calculator prices the broadloom.