Carpet Calculator
Estimate how much carpet you need by area and depth — plus bags and total cost. Switch between imperial and metric units.
Carpet Calculator
Estimate how much you need — and the cost.
- sq meters 10.22
Quick coverage reference
Carpet is sold by the square yard (1 sq yd = 9 sq ft) on 12 ft wide rolls. Sq yards = room area × (1 + waste) ÷ 9.
How it's calculated
- Add about 10% for seams and trimming on a simple room; 15–20% for stairs, hallways, or patterned carpet that must be matched.
Source: inchcalculator.com/carpet-calculator/ (1 sq yd = 9 sq ft, 12 ft roll, waste factors cross-checked)
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</script>How much carpet do I need?
Carpet is sold by the square yard, where 1 sq yd = 9 sq ft, and it comes on rolls that are usually 12 ft wide. You start from the room area, add a waste allowance for seams and trimming, then convert to square yards.
Use area needed = room area (sq ft) × (1 + waste%), then sq yards = area needed ÷ 9. A 12 × 15 ft room is 180 sq ft, or about 22 sq yards with 10% waste. Because broadloom comes 12 ft wide, room layout and seam placement affect how much you really use — wider or oddly shaped rooms can waste more.
How to measure for carpet
Measure each room
Length × width in feet. Measure into closets and doorways where the carpet continues.
Add a waste factor
10% for a simple room; 15–20% for stairs, hallways, and patterned carpet that must be matched across seams.
Convert to square yards
The calculator divides by 9 to give square yards — the unit carpet is priced and sold in.
Plan the seams
Rolls are 12 ft wide, so rooms wider than 12 ft need a seam. Place seams away from doorways and high-traffic lines.
Carpet buying tips
A room just over 12 ft wide forces an extra strip and a seam, which can waste a surprising amount — measure before you assume.
Carpet needs a separate cushion underneath. Buy padding to the same square yardage as the carpet.
Order all the carpet for a job at once. Color varies between dye lots, and matching a later piece is difficult.
Carpet calculator FAQ
How many square feet are in a square yard of carpet?
One square yard equals 9 square feet. To convert square feet to square yards, divide by 9.
How much carpet do I need for a 12x12 room?
A 12 × 12 ft room is 144 sq ft, about 16 sq yards before waste — roughly 18 sq yards with a 10% allowance.
How much extra carpet should I buy for waste?
Add 10% for a simple room, and 15–20% for stairs, halls, and patterned carpet that needs matching across seams.
How wide is a roll of carpet?
Most broadloom carpet comes on 12 ft wide rolls, which is why rooms wider than 12 ft need a seam.
Do I need carpet padding too?
Yes. Carpet sits on a separate cushion. Buy padding to the same square yardage so it covers the whole floor.