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Carpet Calculator

Room area converted to square yards (how carpet is sold), plus a waste allowance for seams and irregular rooms.

Room area (sq ft)

Waste factor (%)

Carpet needed

24.444 yd²

Carpet is sold by the square yard, and comes in standard roll widths — a flooring pro can account for seam placement.

What you entered

Room area (sq ft): 200Waste factor (%): 10

1
Room area with 10% waste
200 × 1.10= 220 sq ft
2
Convert to square yards (carpet is sold by the yard)
220 ÷ 9= 24.4444 yd²

Result

Carpet needed: 24.444 yd²

A 200 sq ft room needs about 24.444444444444446 square yards of carpet.

Square yards of carpet for common room sizes

Carpet is priced by the square yard, so each row converts the room area to square yards by dividing by 9, then shows the same figure with a 10 and 15 percent waste allowance added, as the calculator does. Values are rounded to one decimal.

Room size (ft)	Room area (sq ft)	Carpet, no waste (sq yd)	At 10% waste (sq yd)	At 15% waste (sq yd)
10 x 10 bedroom	100	11.1	12.2	12.8
10 x 12 bedroom	120	13.3	14.7	15.3
12 x 12 bedroom	144	16.0	17.6	18.4
12 x 14 bedroom	168	18.7	20.5	21.5
12 x 16 living room	192	21.3	23.5	24.5
14 x 16 living room	224	24.9	27.4	28.6
15 x 18 living room	270	30.0	33.0	34.5
16 x 20 family room	320	35.6	39.1	40.9
20 x 24 basement	480	53.3	58.7	61.3

Carpet comes off a 12 ft wide roll, so any room wider than 12 ft needs a seam and the roll width, not the room area, drives how much you actually buy: a 13 ft wide room can consume nearly as much carpet as a 24 ft one because of the offcut down the side. Treat these figures as the material in the room and let the installer measure for seam placement before you order. Padding and tack strip are separate purchases, padding by the square yard and tack strip by the linear foot of perimeter. Stairs are extra at roughly 1.5 to 2 sq ft per step, so a 13-step flight adds about 20 to 26 sq ft, or 2.2 to 2.9 sq yd.

Carpet is sold by the square yard, not square foot

Divide square feet by 9 to get square yards — carpet retailers price and sell by the yard, so converting your room measurement to the right unit avoids confusion when comparing quotes.

Roll width affects seam placement

Carpet typically comes in 12-foot-wide rolls — rooms wider than that need a seam, and an installer can help plan seam placement in a low-traffic area rather than the room's center.

Frequently asked questions

My living room is 15x18 ft — how many square yards of carpet do I need?

15 x 18 = 270 sq ft / 9 = 30 sq yards. Add 10% for seams and irregularities: about 33 sq yards. Since the room is wider than 12 feet, one seam is required.

Why is carpet priced per square yard instead of square foot?

It's an industry convention from when carpets were manufactured in yard-width rolls. Divide square feet by 9 to convert. A carpet priced at $4.50/sq yd is equivalent to $0.50/sq ft.

How much extra carpet do I need for stairs?

Each stair step typically needs about 1.5-2 sq ft of carpet (tread + riser). A standard 13-step staircase needs about 20-26 sq ft of additional carpet, plus waste for cuts and wrapping.