Quick Answer
Measure room length and width. Multiply for square feet. Add 10% waste (15% for patterned carpet or stairs). Divide by 9 to convert to square yards (the standard US carpet sales unit). For rooms wider than 12 feet, plan for seams along the longer dimension.
The Basic Calculation
For a 14 × 16 ft bedroom:
- Floor area = 14 × 16 = 224 sq ft
- With 10% waste = 224 × 1.10 = 246 sq ft
- In square yards = 246 ÷ 9 = 27.3 sq yd
- If pricing is $30/yd, total ≈ $820 (material only)
Why Roll Width Matters
Standard broadloom carpet comes in 12-foot-wide rolls. (Some manufacturers also offer 13.5 ft and 15 ft rolls.) If your room is wider than the roll, you need two strips and a seam.
A skilled installer plans seams away from main traffic paths, away from natural light, and parallel to the room's long axis. Patterned carpets force pattern matching across seams — always order 15% extra for these.
Stair Calculation
A standard US stair is 10 inches deep (tread) plus 7 inches tall (riser), and the visible nose adds another 1.5 inches of front-edge wrap. Total carpet per step ≈ 18.5 inches ≈ 1.55 ft.
For a 14-step staircase 3 ft wide:
- Carpet length = 14 × 1.55 ft = 21.7 ft per stair width
- Total area = 21.7 × 3 = 65 sq ft
- With 15% waste = 75 sq ft
2026 Carpet Price Tiers
| Type | Material per Sq Ft | Installed per Sq Ft |
|---|---|---|
| Builder-grade nylon | $1 – $3 | $3 – $6 |
| Mid-range Berber / plush | $3 – $6 | $6 – $9 |
| Premium solution-dyed | $6 – $10 | $9 – $13 |
| Wool (high-end) | $8 – $15 | $12 – $20+ |
Carpet Pad Matters
Skipping the pad to save money cuts your carpet's lifespan in half. Industry standard is 6–8 lb density, 7/16 in thickness pad for most homes. High-traffic stairs use firmer 8 lb pad.
Order the same square footage of pad as carpet. Pad is $0.30–1.00 per sq ft depending on density and moisture-barrier features.