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Carpet Calculator

Calculate carpet, pad, and tack strip quantities for one or multiple rooms — with waste, pattern matching, and material cost.

#1×ft

Carpet Needed (10% waste)

14.7 sqyd

120 sqft total · ~$745 est. cost

Total area120 sqft
Square yards (net)13.3 sqyd
Carpet needed (10% waste)14.7 sqyd
Pad area (+5%)126 sqft
Tack strip (perimeter)44 LF
Seaming tape (est.)12 LF
Carpet (Mid-Range ($5/sqft))~$660
Pad (Standard 6lb ($0.50/sqft))~$63
Tack strip (@ $0.50/LF)~$22
Total materials~$745
info

Mike Callahan:Carpet is sold by the square yard but measured by the square foot — don’t confuse them or you’ll short-order by 9×. And always buy extra for closets, transitions, and seaming waste. I’ve never had a job where the exact calculation was enough.

Methodology

Total area = sum of each room’s length × width. Square yards = total sqft ÷ 9. Carpet with waste = sqyd × (1 + waste%). Pad area adds 5% over room area for overlap. Tack strip = total perimeter of all rooms in linear feet. Seaming tape estimated at 12 LF per room. Costs are material only — labor for carpet installation typically runs $3–$6/sqyd additional. Prices reflect 2026 national averages.

Frequently Asked Questions

What is the difference between square yards and square feet?
One square yard equals 9 square feet (3 ft × 3 ft). Carpet is priced and sold by the square yard, but rooms are measured in square feet. To convert square feet to square yards, divide by 9. A 12×10 room is 120 sqft or 13.3 sqyd. Always double-check which unit a price quote uses — a $5/sqft carpet is $45/sqyd, not $5/sqyd.
How much extra carpet should I buy?
Plan for 10% waste on standard installations with straight runs. Increase to 15% if the carpet has a pattern repeat that needs matching at seams. Rooms with closets, hallways, or irregular shapes generate more scrap. Stairs are especially wasteful — budget 15–20% extra for stairways. Keep leftover carpet for future repairs; a patch from the original roll will match perfectly.
What carpet pad thickness should I use?
For most residential applications, 7/16-inch thick, 6 lb density pad is the standard recommendation and what most carpet warranties require. Premium 8 lb pad adds cushion and extends carpet life in high-traffic areas. Memory foam pad is the most comfortable but costs more and can make rolling office chairs difficult. Never use pad thicker than 7/16 inch under Berber or low-profile carpet — the carpet will buckle and wrinkle.
Do I need to remove old carpet first?
Yes — new carpet should never be installed over old carpet. The old pad traps moisture and allergens, and layering carpet creates an uneven surface that wears unevenly. Remove old carpet, pad, and tack strips. Inspect the subfloor for damage, squeaks, or moisture. Repair any issues before new pad and carpet go down. Most installers include removal in their labor quote at $1–$2/sqyd.

Carpet quantities calculated as total room area ÷ 9 for square yards, plus waste factor. Pad area includes 5% overlap. Tack strip = room perimeters in linear feet at $0.50/LF. Material costs only — does not include installation labor, furniture moving, or old carpet removal. Verify pricing with your local supplier.