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This carpet calculator works out how much carpet to buy for a room. Because carpet comes off rolls of a fixed width, it checks both directions to find the layout with the least waste, then shows the amount to buy in square yards or square meters, the number of widths, and the carpet pad you need.
How to Use the Carpet Calculator
- Measure the room length and width at the widest points, including closets and into doorways.
- Choose the roll width (12 ft is standard in the US; 4 m in the UK and Europe).
- Add an allowance for trimming, and more for patterned carpet.
- Optionally enter the price per square yard or square meter.
How Carpet Is Measured
Square yards = Square feet ÷ 9
Rooms wider than the roll need more than one width (drop) of carpet joined with a seam. The calculator lays the drops in both directions and picks the one that cuts the least carpet.
Example
A 15 × 13 ft room is 195 sq ft, or 21.7 sq yd. With a 12 ft roll, running two widths across the 13 ft side uses 26 linear feet: 34.7 sq yd of carpet. Running them the other way would use 40 sq yd.
Common Roll Widths
| Region | Standard roll widths |
|---|---|
| United States and Canada | 12 ft (most carpet), 15 ft (some styles) |
| UK, Ireland and Europe | 4 m and 5 m |
| Australia | 3.66 m and 4 m |
Carpet Buying Tips
- Buy carpet pad for the room area only; it does not need to match the roll layout.
- Keep seams out of high-traffic paths and doorways when you can.
- Pile direction should run the same way on both sides of a seam.
- Stairs are measured separately: each step usually needs a piece about 18–22 in long.
Comparing flooring options? See our flooring calculator.
Frequently Asked Questions
How much carpet do I need for a 12×12 room?
A 12 × 12 ft room needs exactly one width of 12 ft carpet, 12 ft long: 16 sq yd, plus a little extra for trimming.
How do I convert square feet to square yards of carpet?
Divide square feet by 9. For example, 270 sq ft is 30 sq yd.
How much extra carpet should I buy?
Add about 10% for trimming. Patterned carpet may need 15–20% for pattern matching.
Do I need the same amount of carpet pad?
No. Pad is cut to the room area, so you need about the room’s square yardage.
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