Carpet Calculator — Sq Yards & Cost Estimator

How to Calculate Carpet for Any Room

Carpet is sold by the square yard, but most people measure rooms in feet. The math is simple: measure length × width in feet, then divide by 9 to convert to square yards. Add waste (10–20%), then multiply by the price per square yard. The tricky part is accounting for seams, closets, stairs, and roll widths.

Carpet Cost Comparison (2026, per sq yd)

Carpet Type	Material/sq yd	Padding/sq yd	Install/sq yd	Total/sq yd
Budget / Builder Grade	$5–$10	$3–$4	$4–$6	$12–$20
Plush / Textured	$15–$25	$4–$6	$5–$8	$24–$39
Berber / Loop	$12–$22	$3–$5	$5–$7	$20–$34
Frieze / Twist	$18–$30	$4–$6	$5–$8	$27–$44
Luxury / Wool Blend	$35–$60	$5–$8	$6–$10	$46–$78
Commercial / Low Loop	$8–$18	$2–$4	$4–$6	$14–$28

Understanding Carpet Roll Width

Standard carpet rolls are 12 feet wide. Some styles come in 13.5 ft or 15 ft widths. This matters because any room wider than 12 feet will require a seam. Seams add cost (seam tape), labor, and can be visible — especially with plush carpet.

Pro tip: Orient the carpet so the roll width covers the longer wall when possible. A 10×14 room can be covered seamlessly if you run the 12-ft roll along the 14-ft wall (you'll waste a 2-ft strip, but no seam). Running it the other way would need a seam at 12 feet.

Waste Factor: How Much Extra to Buy

• 10% waste — Simple rectangular rooms, no pattern, standard 12-ft roll width covers the room
• 15% waste — L-shaped rooms, closets, rooms wider than 12 ft (seam waste)
• 20% waste — Patterned carpet (patterns must align at seams), complex room shapes, multiple doorways
• 25% waste — Large patterns with long repeats, rooms with many angles or curves

How to Measure Stairs for Carpet

Each stair step needs enough carpet to cover the tread (the flat part you step on), the riser (the vertical part), plus extra for tucking under the nose. The standard formula:

1. Measure tread depth (typically 10–11 inches)
2. Measure riser height (typically 7–8 inches)
3. Add 1.5 inches for tuck-under at nose and base
4. Total per step: ~30 inches (2.5 feet) of carpet length
5. Multiply by stair width (typically 36 inches)
6. So each step ≈ 7.5 sq ft of carpet
7. Multiply by number of steps, add 10% waste

Padding Matters More Than You Think

Good carpet padding extends carpet life by 50% or more. It absorbs impact, insulates, and makes carpet feel luxurious underfoot. Don't cheap out here.

• 6 lb, 7/16" pad — Minimum for residential. Fine for bedrooms with light traffic.
• 8 lb, 7/16" pad — Best value for most homes. Good for living rooms and hallways.
• 8–10 lb, 1/2" pad — Premium feel. Great for master bedrooms and stairs.
• Berber pad — Use firm, thin (3/8") padding under berber carpet. Thick, soft padding causes berber to buckle.
• Stairs: Use 8 lb minimum padding on stairs for durability and safety (cushions falls).

Money-Saving Tips

• Shop remnants. Carpet remnants (leftover roll ends) cost 50–70% less. Perfect for single rooms under 12×15.
• Buy carpet + padding + installation as a package. Most retailers offer better per-sq-yd pricing on bundled deals.
• Avoid the cheapest padding. Thin padding wears out fast, and you'll replace carpet 3–5 years sooner. Spending $2 more/sq yd on padding saves hundreds long-term.
• Time your purchase. Best carpet deals: Labor Day, Black Friday, and January (post-holiday clearance). Avoid spring — that's peak season.
• Measure carefully. Overestimating by 15% is fine (you want extra). Underestimating means a second roll from a different dye lot — and it won't match.