FlooringCarpet Calculator

Carpet Calculator

Calculate square yards, roll length, seams, pad, installation cost, and waste.

Room and Roll

Quick start

Length (ft)

Run direction

Width (ft)

Across the roll

Roll width

Carpet grade

Ready to calculate

Pick a preset or enter room dimensions

Last updated June 13, 2026 by our expert review team

Carpet for Common Rooms

A typical 12 x 15 ft primary bedroom needs about 22.1 square yards of carpet, or 17 linear feet from a 12 ft roll with 10% waste.

Room	Size	Sq yd	12 ft roll	Installed cost
Small bedroom	10 x 12 ft	17.6 sq yd	14 LF	$721-$1,220
Square bedroom	12 x 12 ft	17.6 sq yd	14 LF	$721-$1,220
Primary bedroom← typical bedroom	12 x 15 ft	22.1 sq yd	17 LF	$901-$1,525
Living room	15 x 20 ft	58.7 sq yd	44 LF	$2,402-$4,066

Computed with mid-grade carpet, memory foam pad, basic installation, and 10% waste. A room wider than 12 ft may need a seam or a wider roll.

Expert Contributors

Creator

Hawkin

Certified Cost & Estimating Professional

Hawkin

Certified Cost & Estimating Professional

AACE-certified estimator working with 20+ insulation companies including the two largest franchises in America.

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Expert Review

Ehsan Ghazanfari

Licensed Structural Engineer

Ehsan Ghazanfari

Licensed Structural Engineer

FISE-certified structural engineer with 11+ years designing bridges, retaining walls, and foundations. MSc from Aalto University.

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Updated June 2026

How we verify our calculators

Seam math

Why Roll Width Changes the Order

A 13 ft wide room cannot be cut from one 12 ft wide roll. The missing 1 ft strip usually means a second full-length cut.

Carpet roll width seam diagram showing a thirteen foot wide room cut from a twelve foot carpet roll. — A 13 ft room may need two full-length cuts from a 12 ft roll, while a 15 ft roll may avoid that seam.

12 ft vs 15 ft Roll Decision

Carpet roll width decides the cut plan. CRI notes that carpet installation plans should include measurements, seam placement, carpet direction, and special areas such as closets or unusual room shapes.

Choice	Best when	Watch item
12 ft roll	Rooms 12 ft wide or less, halls, smaller bedrooms	A 13 ft room usually needs a seam.
15 ft roll	Rooms 13 to 15 ft wide where one cut avoids a seam	May cost more or have fewer style choices.
Seamed layout	Large rooms wider than available broadloom	Keep pile direction aligned and seams out of traffic.

Typical Cost Stack

$3.25–$10.7

installed, per sq ft

Carpet: $2-$8/sq ft
Pad: $0.5-$1.8/sq ft
Labor: $0.75-$1.5/sq ft

Retail offers vary. Separate material, pad, labor, removal, stairs, and minimum charges before comparing quotes.

Methodology

How the Carpet Calculator Works

The calculator measures the room, divides the room width into roll-width strips, then turns those strips into linear feet of carpet roll. That is why a room just over 12 ft wide can jump to two full-length cuts.

Square yards lead the result because carpet is often quoted that way. Cost is calculated from the ordered area, then split into carpet, pad, and basic installation labor.

This is an estimating layout, not a seam diagram for installation. Final cuts should come from the installer after checking pile direction, closets, doorways, stairs, and natural light.

Formulas

Measured sq ft = room length x room width + stairs x 12

Strips = ceil(room width / roll width)

Ordered sq ft = (strips x room length x roll width + stair area) x (1 + waste %)

Roll LF = ceil((strips x room length + stair area / roll width) x (1 + waste %))

Square yards = ordered sq ft / 9, rounded up for ordering

Stairs use 12 sq ft each for planning. Roll-width overage is counted before the waste override.

Carpet Quick Reference

1 square yard: 9 sq ft
Common roll widths: 12 ft, 15 ft
Typical waste: 10%
Stair allowance: ≈ 12 sq ft each
Seam rule: minimize and align pile

Carpet Project Examples

Guest bedroom

10 x 12 ft, 12 ft roll, mid-grade carpet

17.6 sq yd14 roll LF$721-$1,220

This room fits across a 12 ft roll with no field seam, but you still buy the full roll width.

Wide family room

13 x 20 ft, 12 ft roll, seam required

58.7 sq yd44 roll LF$2,402-$4,066

A 13 ft width needs two 20 ft cuts from a 12 ft roll unless a 15 ft broadloom option is available.

Bedroom plus stairs

12 x 12 ft room plus 12 stairs

35.9 sq yd27 roll LF$2,242-$3,645

Stairs add material and labor. Use the stair count here for carpet, then check rise and run separately.

Premium primary suite

15 x 20 ft, 15 ft roll, premium carpet

36.7 sq yd22 roll LF$2,294-$3,729

A 15 ft roll can remove the seam that a 12 ft roll would create in the same room.

Avoid these

Carpet Measuring Mistakes

Entering square footage only

Carpet roll width matters. A 13 ft wide room can need two full-length cuts from a 12 ft roll, even when the raw square footage looks small.

Ignoring closets and alcoves

Measure wall to wall and include closets, returns, and landings. Small missing areas can force a second cut later.

Turning one piece sideways

Broadloom pieces usually need the pile running the same direction. Rotating a fill strip can make the seam show.

Putting seams in traffic lanes

Keep seams to a minimum and avoid doorways, pivot points, and strong cross-light where possible.

Carpet Installation FAQ

How much carpet do I need for a 12 x 12 room?

A 12 x 12 room needs about 17.6 square yards of carpet when ordered from a 12 ft roll with 10% waste. That is 14 linear feet of 12 ft roll.

How many square feet are in a square yard of carpet?

One square yard of carpet is 9 square feet. Carpet is often priced by square foot in retail ads, but installers and older quotes may still use square yards.

How much does carpet installation cost?

A mid-grade carpet job often lands around $901-$1,525 for a 12 x 15 ft room in this calculator, including carpet, pad, and basic installation. Your quote can change with furniture moving, removal, stairs, subfloor repair, and minimum labor charges.

Should I choose 12 ft or 15 ft carpet?

Use the width that creates the cleanest layout, not just the cheapest square-foot price. A 15 ft roll can remove seams in 13 to 15 ft rooms, while a 12 ft roll may still be cheaper if the seam is acceptable and the pile direction works.

Can carpet seams be invisible?

No seam is guaranteed invisible. CRI guidance says seams should be minimized, run with the length of the area when possible, and avoid traffic pivots, doorway openings, and cross-light.

How much carpet do stairs need?

Plan about 12 square feet per stair for a rough takeoff, or 3 ft by 4 ft per step. Stairs need installer review because tread depth, riser height, nosing, landings, pattern, and pile direction change the cuts.

Do I need carpet pad?

Yes for most stretch-in residential carpet. The Carpet and Rug Institute describes cushion as important to carpet life, except for direct glue-down systems where the manufacturer says otherwise.

Should I buy carpet by square feet or square yards?

Both describe area, but square yards are common for carpet because 1 square yard equals 9 square feet. This calculator leads with square yards and also shows roll linear feet because roll width controls the cut plan.

Carpet Planning Tips

Ask the installer to mark seams on the estimate. The CRI 105 residential standard says seam placement should consider traffic, light, doorways, and pile direction.

Compare carpet by total installed cost, not only the advertised carpet price. Pad, removal, stairs, furniture moving, and minimum labor charges can change the final quote.

Include closets and landings in your measurements. For odd-shaped rooms, use the square footage calculator, then come back here for roll-width math.

Carpet and pad are different from plank flooring. Use the flooring calculator for boxes of laminate, vinyl, hardwood, or tile.

Important Disclaimer

These estimates are for planning purposes only. Actual costs vary by location, material availability, and project complexity. Always get at least 3 local quotes. This calculator does not replace professional advice.