Carpet Calculator — How Much Carpet Do I Need?
Enter your room size to get the exact carpet area in square feet and square yards, with waste included. No sign-up, no data stored.
Carpet needed
How carpet quantity is calculated
The math is simple and exact — no assumptions to adjust for:
- Area = room length × width (in square feet or meters).
- With waste = area × (1 + waste%).
- Square yards = area ÷ 9 — this is how carpet is priced and sold.
- Cost = square yards × price per square yard (only if you enter a price).
Residential carpet comes on 12-foot-wide rolls. If your room is wider than the roll, you need a seam — which adds waste and a bit of labor. For patterned carpet, allow extra so the pattern lines up at every seam.
Carpet reference chart
Roll widths, waste factors, and typical pricing.
Carpet roll widths
| Roll width | Best for |
|---|---|
| 12 ft | Standard rooms up to 12 ft wide |
| 13.5 ft (4 m) | Metric roll, wider rooms |
| 15 ft | Large rooms, less seaming |
Typical waste by layout
| Layout | Add for waste |
|---|---|
| Simple rectangle | ~5% |
| Standard room | ~10% |
| Staircases / hallways | ~15% |
| Patterned carpet | ~15–20% |
Typical carpet cost (US)
| Grade | Per square foot | Per square yard |
|---|---|---|
| Budget | $2–4 | $18–36 |
| Mid-range | $3–6 | $27–54 |
| Premium | $6–10+ | $54–90+ |
Last updated: October 2026 · Prices are typical US ranges and vary by retailer and region. Always confirm roll width and get a written quote from your installer before ordering.
Carpet calculator FAQ
The room is 144 sq ft = 16 sq yd. Add 10% waste for about 18 sq yd. A 12×12 room fits one 12-ft-wide strip with little waste.
Carpet is priced and sold by the square yard. You measure the room in square feet, then divide by 9. Some retailers also quote a square-foot price — be sure you compare the same unit.
Because carpet is sold in 12-ft-wide rolls. If the room is wider or has stairs, alcoves, or a pattern, you can't use every inch of the roll — the unused edges are the "waste."
Yes. A little extra covers seaming, cuts, and future repairs, and it's cheaper to buy now than to match a dye lot later. About 10% extra is a safe rule for a standard room.
Yes. Carpet is installed over a carpet pad (about 7–8 lb density is standard). Padding adds comfort, insulation, and extends carpet life. It's usually sold separately by the square foot or yard.