A 12 × 15 ft room (180 sq ft, 20 sq yd) takes 20.7 sq yd of carpet — 15.5 linear ft off a 12 ft roll, no seam.
| Roll · runs | Drops | Seams | Sq yd | Offcuts |
|---|---|---|---|---|
| 12' · 15' | 1 | 0 | 20.7 | 3% |
| 12' · 12' | 2 | 1 | 33.3 | 40% |
| 13' 6" · 15' | 1 | 0 | 23.3 | 14% |
| 13' 6" · 12' | 2 | 1 | 37.5 | 47% |
| 15' · 15' | 1 | 0 | 25.8 | 23% |
| 15' · 12' | 1 | 0 | 20.8 | 4% |
Only some styles come in 13 ft 6 in or 15 ft widths — ask before you pick one.
Carpet: Home Depot LifeProof typical (cached 2026). Pad: Caldwell full-roll memory-foam rebond. Tap any price to enter your store's.
This Old House (June 2026): labor $0.50–$1 per sq ft, stairs $11–$26 extra per step, removal $2–$3 per sq ft. “Free install” promos often exclude stairs, removal and furniture moving.
| Roll width | Roll runs along | Seams | Sq yd | Offcuts |
|---|---|---|---|---|
| 12 ft | 15 ft wall | 0 | 20.7 | 3% |
| 12 ft | 12 ft wall | 1 | 33.3 | 40% |
| 13 ft 6 in | 15 ft wall | 0 | 23.3 | 14% |
| 13 ft 6 in | 12 ft wall | 1 | 37.5 | 47% |
| 15 ft | 15 ft wall | 0 | 25.8 | 23% |
| 15 ft | 12 ft wall | 0 | 20.8 | 4% |
On a 12 ft roll this room already needs no seam; the best wider roll (15 ft) would mean buying 20.8 sq yd, so it only adds offcuts.
A single piece means no seam to show — the best result for a bedroom.
The full method, material data and tips are on the main carpet calculator page.