Mis à jour July 2026

Carpet Square Footage Calculator

Measure your room, add a waste allowance for seams and cuts, and see how many square feet — and square yards — of carpet to order.

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Longueur de la pièce

Largeur de la pièce

Facteur de perte

5–10% habituel

Couverture par boîte

sq ft

Facultatif

Surface au sol

180sq ft

À commander (+perte)

198 sq ft

Commandez toujours la quantité ajustée pour les pertes afin d'avoir assez pour les coupes, les erreurs et les réparations futures.

Ce que cela signifie

To calculate carpet square footage, measure the room's length and width in feet and multiply them (length × width). Add about 10% for waste from seams, cuts, and pattern matching. Because carpet is often sold by the square yard, divide the total by 9 to convert square feet to square yards. Plan a seam for any room wider than the roll — 12 ft is the typical carpet width.

Formule et guide

Comment le calcul est effectué

Carpet is measured as floor area — length times width. Because carpet ships on wide rolls and is priced two ways, you also add waste and convert to square yards before ordering.

1Measure the room's length and width in feet (round up to the nearest half-foot).
2Multiply length × width to get the floor area in square feet.
3Add roughly 10% for waste from seams, cuts, doorways, and pattern matching.
4Divide the total by 9 to convert square feet to square yards if the store prices that way.

Exemple résolu

En chiffres

Room (12 ft × 15 ft)	180 sq ft
+ 10% waste	≈ 198 sq ft
Convert to sq yd (÷ 9)	≈ 22 sq yd
Order	22 sq yd

A 12 × 15 ft room is 180 sq ft; + 10% waste ≈ 198 sq ft, or about 22 sq yd of carpet to order.

Précision et hypothèses

A ~10% waste factor covers seams, cuts around doorways, and pattern matching.
Carpet rolls are typically 12 ft wide; rooms wider than the roll need a planned seam.
Stairs, closets, and hallways add area and should be measured and included separately.
Many stores price and sell carpet by the square yard, so divide square feet by 9.

Conseils et règles clés

Area in square feet = length × width; measure the widest points of an irregular room.
Carpet is sold both by the square foot and the square yard — 1 sq yd = 9 sq ft.
Standard broadloom rolls are 12 ft wide (15 ft is also common), which decides seam placement.
A 10% waste allowance is typical; use more for stairs, angled rooms, or patterned carpet.

Cas d'usage

À qui s'adresse cette calculatrice

Bedrooms and living rooms

Measure length × width, add 10% waste, and convert to square yards for a quote.

Stairs and landings

Measure each tread and riser, total the area, and add it to the room figure.

Estimating cost

Multiply the square yardage (or square footage) by the price per unit to budget the job.

How to calculate the square footage of carpet

Carpet square footage is simply the floor area you want to cover, measured in square feet. For a rectangular room, measure the length and width in feet and multiply them together — a 12-foot by 15-foot room is 180 square feet. For an L-shaped or irregular room, split the floor into rectangles, calculate each one, and add them up. Measure at the widest points and round up to the nearest half-foot so you never come up short.

Once you have the raw floor area, add roughly 10% for waste. Carpet is trimmed to fit walls, cut around doorways and closets, and — for patterned styles — aligned so the design matches across pieces. That 10% covers the offcuts you can't reuse. The calculator above does the multiplication and the waste factor for you; this is the same approach used for a broader flooring estimate.

Square feet, square yards, and roll width

Carpet is one of the few flooring materials still commonly priced by the square yard, a holdover from how broadloom is manufactured. To convert, divide your square footage by 9, because one square yard equals nine square feet. Our 198-square-foot example becomes about 22 square yards. Always confirm which unit the store quotes so you're comparing prices on the same basis.

Roll width also shapes your order. Broadloom carpet typically comes on 12-foot-wide rolls, so any room wider than 12 feet will need a seam where two pieces meet. Plan the seam to run along the length of the room and away from high-traffic sightlines. A wider 15-foot roll can sometimes cover a large room seamlessly but produces more waste on narrower spaces.

From square footage to a real budget

Knowing the area is the first step; turning it into a number you can plan around is the second. Take your final square footage (or square yardage) and multiply it by the installed price per unit, which usually bundles the carpet, the pad, and labor. Don't forget the extras that measurements miss — stairs, closets, and transition strips at doorways all add to the total.

For a full project estimate, feed your carpet area into the cost calculator with your price per square foot or square yard. If you're carpeting a whole home, measure each space with the room calculator first, then total the areas before applying waste so a single order covers the job.

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FAQ

FAQ de la calculatrice Carpet

Measure the room's length and width in feet and multiply them: a 12 × 15 ft room is 180 square feet. Then add about 10% for waste from seams, cuts, and pattern matching, which brings it to roughly 198 square feet. For irregular rooms, split the floor into rectangles, calculate each, and add the areas together.

Divide the square footage by 9, since one square yard equals nine square feet. For example, 198 square feet ÷ 9 is about 22 square yards. Carpet is often priced by the square yard, so this conversion lets you compare quotes and order the right amount. Round up to the next whole yard to be safe.

Add roughly 10% to your measured floor area for waste. That allowance covers trimming to fit walls, cuts around doorways and closets, and matching patterns across seams. Use a higher figure — 15% or more — for stairs, angled or L-shaped rooms, and boldly patterned carpet, since those layouts create more unusable offcuts.

Yes. Stairs add real area you have to cover, so measure them separately and add them to the room total. For each step, measure the tread (the part you walk on) plus the riser (the vertical face) and total them. As a rough guide, a standard stair uses about 1.5 to 2 square feet per step.

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