Carpet Calculator

Measure your room's length and width in feet and type them in — the carpet calculator instantly shows the square feet and square yards you need, with a 10% waste allowance already included. That's it for the common case. Need more control? Open More options to switch to metric (meters), change the waste allowance, or enter a price per square yard to estimate the total cost. For an L-shaped room, split it into rectangles, run each one, and add the results together.

Rooms are measured in square feet, but carpet in the US is sold and priced by the square yard. One square yard equals 9 square feet, so a 180 sq ft room is 20 sq yd. Because carpet comes on wide rolls (usually 12 ft) and installers need extra material for seams, trimming, and pattern matching, you always buy more than the bare room size. This is why every reputable carpet estimate adds a waste factor — typically 10% for a simple rectangular room, and up to 20% for stairs, hallways, or carpet with a repeating pattern.

The math is a two-step area calculation:

1. Room area = length × width
2. Total with waste = room area × (1 + waste% ÷ 100)
3. Square yards = total sq ft ÷ 9, then rounded up to the next whole yard

Example: a 15 ft × 12 ft room = 180 sq ft. Add 10% waste → 198 sq ft. Divide by 9 → 22 sq yd. If carpet is $30/sq yd, that's 22 × $30 = $660 in carpet.

How much carpet for a 12x12 room? 12 × 12 = 144 sq ft, +10% = 158 sq ft ≈ 18 sq yd.

How much carpet for a 10x10 bedroom? 10 × 10 = 100 sq ft, +10% = 110 sq ft ≈ 13 sq yd.

Carpet for a 20x15 living room: 20 × 15 = 300 sq ft, +10% = 330 sq ft ≈ 37 sq yd.

Carpet by the square yard for a 14x14 room: 196 sq ft, +10% = 216 sq ft = exactly 24 sq yd.

- Measure at the widest points and into every closet or alcove you plan to carpet.
- Use 10% waste for a plain rectangular room, 15% for hallways or diagonal layouts, and 20% for stairs or patterned carpet.
- Carpet rolls are usually 12 ft wide — a room wider than 12 ft will need a seam, which slightly increases waste.
- Get your quote priced per square yard, not per square foot, so it matches how stores sell it.
- Add roughly $3–$6 per sq yd for padding and $4–$8 per sq yd for installation when budgeting the full job.