Carpet is sold by the square yard
Carpet pricing still quotes in square yards (9 sq ft each) even though rolls are 12 feet wide. The calculator converts your room area to both units and applies the per-unit price — remember to add pad ($0.50–1.50/sq ft installed), tack strips and the installer's per-yard labor.
The 12-foot roll and the seam problem
Carpet rolls are 12 feet wide, so rooms wider than 12 feet need a seam. A 15×20 room lays as one 12-ft width plus a 3-ft strip seamed along the long axis — plan seams away from traffic lanes and toward the light. Direction of the pile must run the same way on every piece or the seam shows forever.
Carpet is the one flooring sold by the square yard
Tile, hardwood, vinyl and laminate are all quoted by the square foot. Carpet is not, and that single fact causes more estimating errors than any other part of the job. The reason is historical: broadloom was woven on wide looms and sold off the roll by the yard, and the trade never switched.
Everything on this page comes from three steps:
- Area.
square feet = length (ft) × width (ft) - Convert.
square yards = square feet ÷ 9, because one square yard is 3 ft × 3 ft - Add waste.
order = square yards × (1 + waste)
The conversion is where people get burned in the other direction. A price of $3 per square foot is $27 per square yard — not $3. If you compare a quote in square yards against a quote in square feet without converting, the difference looks like a factor of nine and it is not a discount.
Worked example: a 12 × 15 ft bedroom
Take the most common master bedroom size in the US. The room measures 12 ft by 15 ft.
- Area: 12 × 15 = 180 sq ft
- Square yards: 180 ÷ 9 = 20 sq yd
- Add 10% for normal cutting waste: 20 × 1.10 = 22 sq yd, which is 198 sq ft
Because the room is exactly 12 ft wide, it fits a standard 12 ft roll in one piece — roughly 15 linear feet of roll, no seam. Padding is ordered on the raw floor area (180 sq ft = 20 sq yd), not the waste-inflated figure, because pad scraps can be butted together without showing through the carpet.
At mid-grade pricing that works out to 198 sq ft of carpet at about $3.50 per sq ft ($693) plus 180 sq ft of pad at about $0.60 ($108) — call it $800 in material. Add labour at $1–$2 per sq ft and the same room typically quotes $900–$1,500 fully installed. The room in a 13 ft width — one foot wider, 15 sq ft more floor — can quote higher than both, for the reason in the next section.
Roll width decides the seam, and a 13 ft room is the expensive one
Broadloom ships in fixed widths: 12 ft is the residential standard, 15 ft is the wide roll, and 6 ft exists for narrow halls and stairs. You cannot stretch carpet, so any room dimension larger than the roll width forces a second strip and a seam.
That makes the worst-value room in any house the one that is just wider than the roll. A 13 ft room cannot take one 12 ft strip. It takes a full-length 12 ft strip plus a 1 ft fill strip cut from another full-length run — so the material roughly doubles for one extra foot of floor. A 15 ft roll solves it in one piece, usually for 10–20% more per square yard than the standard width, and with fewer style choices.
Where a seam is unavoidable, placement is not cosmetic. Keep it:
- Out of walkways — the main path from the door is where a bad seam fails first
- Parallel to the light — seams running with window light are far less visible than seams across it
- Away from doorways — a seam perpendicular to a threshold takes concentrated traffic
- Aligned with pile direction — every piece must run the same way or the seam shows as a colour change
Waste factor by room shape
| Room situation | Roll fit | Waste to add |
|---|---|---|
| Simple rectangle, 12 ft wide or less | One strip, no seam | 10% |
| 12–15 ft wide, 12 ft roll | One seam | 15% |
| 12–15 ft wide, 15 ft roll | One strip, no seam | 10% |
| L-shaped, alcoves, several doorways | Two or more cuts | 15–20% |
| Berber, striped or patterned (repeat match) | Direction locked | 20% |
| Large room, more than one field seam | Multiple cuts | 20% |
Patterned and directional carpet is the case people under-order most often. A Berber loop or a wide stripe looks visibly wrong if one piece runs across the pile and the next runs with it, so every cut has to be taken in the same direction and the off-cuts cannot be reused elsewhere in the room.
What carpet actually costs in 2026
Retail quotes bundle three lines that are worth separating before you compare them, because the cheapest headline price is usually the one with the thinnest pad and the shortest labor allowance.
| Line item | Typical range (per sq ft) | Notes |
|---|---|---|
| Carpet — builder-grade polyester | $2 – $4 | 5–8 year life, mats in walkways |
| Carpet — mid-grade nylon | $3 – $6 | 8–12 years, the common residential choice |
| Carpet — premium nylon | $5 – $8 | 12–18 years, holds up in stairs and halls |
| Carpet — wool or wool blend | $8 – $14 | 15–25 years, premium price and care |
| Pad — 6–8 lb rebond, 7/16 in | $0.30 – $1.00 | Most warranties require new pad with new carpet |
| Installation labor | $0.50 – $2.00 | High end covers stairs and complex layouts |
| Stairs, billed per tread | $15 – $40 each | On top of the per-square-foot rate |
| Seam labor | $1 – $3 per linear ft | A single seam is usually $20–$60 on a bedroom |
Multiply any per-square-foot figure by 9 to compare it against a per-square-yard quote. Material in square yards runs roughly $18–$72 per sq yd for the residential grades above.
Measuring so the order is right the first time
Measure the longest dimension of each wall and write down every room separately — a single total square footage is useless for carpet, because cuts cannot be swapped between rooms with different shapes. Practical rules that survive contact with real installers:
- Measure wall to wall at the widest point, including into doorways and closets. Subtract nothing for furniture; the carpet still has to pass underneath it.
- Treat closets as separate rectangles. They are usually the reason a room that "fits one strip" suddenly needs a second cut.
- Check the width against the roll before anything else. If the narrow dimension is over 12 ft, decide now between a 15 ft roll and a seamed layout — not after the order is placed.
- Stairs are measured in pieces, not area. A standard 3 ft wide stair with a 10 in tread and a 7 in riser needs about 4.3 sq ft of carpet per step, so one linear foot of 12 ft broadloom covers roughly three steps. Count each step, then add the landing as a normal rectangle.
- Round up, never down. Carpet from a different dye lot will not match, so a short order is a second trip and a visible mismatch.
Common mistakes that show up on the invoice
- Comparing a square-yard quote against a square-foot quote. Multiply the per-foot price by 9 first, or the comparison is meaningless.
- Reusing the old pad. It voids most carpet warranties and the compressed traffic lanes telegraph through the new carpet within months. Pad is the cheapest line on the invoice and the biggest factor in how the floor feels.
- Ordering 10% waste on a patterned carpet. Pattern match needs 20%; under-ordering leaves you with a seam that does not line up or a room short of material.
- Choosing carpet before checking the roll width. The width is a property of the product, not a preference, and it decides whether your room gets a seam.
- Ignoring the moisture test on concrete. A slab passing moisture up through the pad grows mould under the carpet within weeks. Get the slab tested before the pad goes down.
- Forgetting trim materials. Transition strips between rooms, tackless strip around the perimeter and stair rods are separate line items — budget another $100–$200 on a typical bedroom.
- Assuming stairs are included. Most quotes price stairs by the tread on top of the square-foot rate. Get it in writing.
Tools for fitting carpet
Carpet is the one flooring job where the tools decide whether the seams stay flat. Everything below is the small kit that a stretch-in installation actually needs.
- Knee kicker — Hooks the carpet onto the tackless strip at the starting wall. Without one, the carpet is never tight enough to stop wrinkling in traffic lanes.
- Power stretcher — A knee kicker only sets the start. Stretching the field across the room is what stops the carpet relaxing and rippling a year later.
- Carpet seam roller — Run over every seam while the adhesive is open. It seats the tape and is the cheapest insurance against a visible seam.
- Carpet trimmer and tackless strip — For trimming along the wall without scoring the skirting, and for the gripper rod that holds the stretched carpet at the perimeter.
As an Amazon Associate I earn from qualifying purchases. The links above are affiliate links — if you buy through one, the price you pay is unchanged and a small commission helps keep these calculators free. Tools are listed because the job calls for them, not because of commission rates.
Sources and standards
Where these figures come from
Every formula on this page is implemented from the published reference material below. Where a value depends on a regional code, the calculator lets you override it rather than assuming one jurisdiction.
- Tile Council of North America — the TCNA Handbook installation methods referenced here.
- Carpet & Rug Institute — carpet installation standards and performance testing.
- US Environmental Protection Agency — volatile organic compound limits for paints and coatings.
- HomeAdvisor True Cost Report — installed cost data for carpet, pad and labour by grade.
Figures, formulas and reference tables last verified: 21 September 2026