Standard sizes: 5×8, 6×9, 8×10, 9×12, 10×14, 12×15 and 12×18 ft. For furniture, leave at least the front legs on the rug.
How to use this calculator
Enter the room length and width and the gap you want between the rug and the walls. The calculator shows the largest rug that fits and the best standard rug size.
The formula
Largest rug = room length − 2 × gap and room width − 2 × gap
The best standard size is the largest rug that fits inside this space.
Example: A 14 ft × 12 ft room with an 18 in gap fits a rug up to 11 ft × 9 ft. The best standard size is 8 × 10 ft, which leaves a gap of 2 ft on every side.
How to pick the right rug size for your room
The rug size calculator finds the largest rug that fits your room while leaving an even border of bare floor. The largest rug result is a limit, not a target. The best standard size is the biggest common rug that fits inside that limit. Leaving a border frames the rug and keeps the room from feeling crowded.
What changes the result
- Room size. Measure wall to wall at floor level, not around furniture.
- Border width. A 24 inch gap gives a smaller rug and more visible floor. A 12 inch gap gives a larger rug.
- Furniture layout. The rug often defines a seating or dining zone rather than the whole room.
Two examples
A 14 by 12 foot room with an 18 inch gap has space for a rug up to 11 by 9 feet. A 9 by 12 foot rug is too long for that space, but an 8 by 10 foot rug fits with room to spare.
A 15 by 12 foot room with a 24 inch gap leaves 11 by 8 feet. An 8 by 10 foot rug still fits, but the border along the long walls is tighter than in the first example.
Tips and common mistakes
- Do not buy a rug that is too small. A common mistake is a small rug floating in the middle of a seating area.
- Mark the size with painter’s tape on the floor before you buy. It shows how the rug will sit with your furniture.
- Check door swing. A thick rug can block a door that opens into the room.
- In open rooms, size each rug to its zone, such as the sofa group or the dining table.
Buying advice
Larger rugs cost a lot more than smaller ones, so decide where size matters most. If the ideal size is too costly, a natural fiber rug such as jute in a larger size can be a cheaper base, with a smaller rug layered on top. Always use a rug pad. It keeps the rug from slipping and protects the floor. Choose a pad about 1 inch smaller than the rug on each side so it does not show.

