Carpet Calculator - Roll Strips, Square Feet & Cost

Carpet Quantity Quick Reference

Ordered carpet (after roll-strip waste) for common rooms, assuming a 12 ft wide roll - the US default. Use this for the dealer-side conversation; the calculator handles your real roll width and room shape.

When the room width is just over the roll width (say 13 ft for a 12 ft roll), you order two strips - the wasted inch is the price of the seam-free option. Sometimes a 15 ft wide roll is worth chasing for one of those rooms.

How Carpet Math Actually Works

Carpet does not come in boxes. It comes off a giant roll, typically 12 ft wide, less commonly 13 ft 2 in (Berber) or 15 ft (wide goods). The estimator unrolls strips down the room length and counts how many it takes to cover the width.

For a 14 x 16 ft room with a 12 ft roll: lay the first 14 ft strip - it covers 12 ft of width. You still have 2 ft uncovered, so you need a second strip 14 ft long. That second strip is 2 ft of useful coverage and 10 ft of waste (or a smaller offcut you may use in a closet). Ordered area is 2 strips x 14 ft x 12 ft = 336 sq ft, even though the room is only 224 sq ft. The carpet you actually pay for is much bigger than the room.

That is why narrow rolls can be more expensive in total than wider rolls, even at a lower per-yard price. The calculator does this math automatically, so you can compare 12 ft and 15 ft roll options side by side.

Square Feet vs Square Yards - The Pricing Trap

US carpet is famously quoted in square yards (because rolls are 12 ft wide x 3 ft = 4 sq yd per linear foot - it counted easily on a tape measure before computers). 1 sq yd = 9 sq ft, so a $40 / sq yd quote is $4.44 / sq ft. The calculator shows both; just make sure your input price matches your input area unit.

UK and Europe sell carpet by the square metre. India, the Middle East, and Australia mostly use square metre as well. Indian retail also sees square-foot pricing in residential markets. When comparing imported and domestic carpets, convert before deciding - a low-yard price on a narrow roll often loses to a higher-yard price on a wider roll once the strip-waste math is done.

Carpet Fibre Types

Pile Style and Use Case

• Cut pile (plush, Saxony): sheared yarn tips, soft feel, shows footprints and vacuum lines. The bedroom default.
• Loop pile (Berber, level loop): yarn loops left uncut. Tough, hides traffic patterns, cooler underfoot. Stair runners and rec rooms.
• Cut and loop: alternating cut and loop creates patterns and texture. Hides wear; pattern-matching adds 5-10% to the order.
• Frieze (twist): highly twisted cut pile, casual look, hides footprints. Family rooms, kid rooms.
• Texture / textured plush: the modern bedroom default - less formal than Saxony, slightly twisted.

Pad / Underlay - The Floor Under The Floor

Carpet pad doubles the comfort and warranty life of the carpet. Skipping or under-spec'ing pad is the silent reason cheap carpet looks tired in two years.

• Rebond foam (6-8 lb density): the US residential default. Multi-colour bonded scrap foam. About $0.40-0.80 per sq ft.
• Memory foam / prime urethane: softer feel, better cushion. Higher cost.
• Rubber slab / waffle: denser, longer life, used commercially or on stairs.
• Felt / fibre: wool-felt under wool carpet. Premium installations.

Match the pad thickness to the manufacturer's spec: residential carpet typically wants 7/16 in pad at 6-8 lb density. Going too thick (more than 1/2 in) actually voids many warranties because the carpet flexes too much at the seams.

Cost Estimates Around The World

2026 retail planning prices for mid-tier residential carpet. Wool and designer carpet sit well above this.

Brand reference: US - Shaw, Mohawk, Beaulieu, Stainmaster, SmartStrand; UK - Brintons, Cormar, Cavalier, Westex; Australia - Godfrey Hirst, Feltex; India - Welspun, Asiatic, Carpet Cellar (commercial), Obeetee (premium hand-knotted wool). Installers charge separately for pad, seam tape, and tackless strips - usually folded into the per-sq-ft labour rate.

Common Mistakes

• Comparing a $/sq yd price against a $/sq ft price without converting (1 sq yd = 9 sq ft).
• Ordering only room area without accounting for roll-strip waste - you pay for the unused offcut.
• Using 12 ft roll width when the product comes 13 ft 2 in - the math changes.
• Placing a seam in the main walking lane of the room - guaranteed wear pattern in 2-3 years.
• Skipping the pad spec or going too thick - both shorten carpet life.
• Picking polypropylene loop for a high-traffic stair - it flattens fast.
• Forgetting transition strips at doorways - they cost $5-20 each and seal the carpet edge.
• Buying mismatched dye lots for connecting rooms - the seam shows colour banding.

Related Construction Calculators

For hard flooring (LVP, laminate, engineered wood), see the Flooring Calculator. For ceramic and porcelain tile, switch to the Tile Calculator. Floor area cleanup starts in the Square Footage Calculator. More tools live on the Construction Calculators hub.