CARPET
About this calculator
This carpet calculator gives you the square yards of carpet (and pad) needed for a room. Carpet is sold by the square yard from rolls 12 or 15 feet wide; the roll width determines whether your room can be covered seamlessly or whether you need a seam. Enter your room length and width, choose a roll width, and the calculator returns square yards to buy with a 10% waste factor plus a rough seam count. One square yard equals nine square feet; pricing is almost always quoted per yd² at retail and per ft² at warehouse outlets.
How to use this calculator
Measure your room length and width in feet. For an L-shaped or stepped room, use the L-shape toggle and enter the cutout. Pick the roll width — 12 ft is the standard residential carpet roll; 15 ft is wider and stocked for large rooms (great room, master bedroom) where you don't want a seam. Choose whether to include carpet pad in the materials estimate.
The result is square yards to buy with a 10% waste factor (carpet is sold by the yd², not the ft²) plus a rough seam count based on whether the room's narrow dimension exceeds the roll width. Pad coverage matches the carpet area. Most installers charge $1–3 per linear foot for seaming, so a single seam adds $20–60 in labor on a typical bedroom.
Worked example
For a 16 × 13 ft bedroom (208 ft²) with 12-ft roll, including pad:
Square feet to buy: 208 × 1.10 = 229 ft². In yards: 229 ÷ 9 = 25.4 yd² → buy 26 yd².
Seam check: short side is 13 ft, roll is 12 ft → 1 seam needed.
At $3–$8/ft² for retail carpet ($27–$72/yd²), materials run $700–$1,800. Pad adds $0.40–$0.80/ft² ($90–$185 for 229 ft²). Pro install adds $0.50–$1.50/ft² in labor plus the $20–$60 seam charge.
For a 12 × 11 ft room (132 ft²) with 12-ft roll: short side fits the roll, so zero seams. That's why room layout matters — a 12 × 11 ft room is cheaper to install than a 13 × 11 ft room of nearly equal area.
Common mistakes & waste factors
Forgetting the room is sold to you in yards but the room measures in feet. 1 yd² = 9 ft², so a 200 ft² room is only 22.2 yd² — confirm pricing units before you sign.
Skipping the pad. New carpet over old hard pad gets 30–50% less life. Pad is the cheapest part of the install and the biggest factor in how the carpet feels and lasts.
Underordering on pattern carpet. Patterned or directional carpet (Berber loops, wide stripes) needs the same direction across all pieces — adds 15–20% waste, not 10%.
Forgetting transition strips and tackless. T-moldings between rooms ($15–$30 each) and tackless strip around the perimeter ($1/lin ft) add up. Budget another $100–$200 in trim materials for a typical bedroom.
Rules of thumb
1 yd² = 9 ft². Always confirm whether you're being quoted per yd² or per ft².
Standard rolls: 12 ft (most common) and 15 ft (wide). 13'2" exists for European patterned carpet and is rare.
10% waste for plain carpet, 15–20% for patterned or directional.
Seam labor runs $1–3 per linear foot. A 13-ft seam adds about $40 to your install.
Carpet life: builder-grade nylon 5–7 years, mid-grade 8–12, premium 15–20. Pad always wears out faster than the carpet — replace both together.
Common questions
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