Enter the room and roll width to get the length to order, including unavoidable seams.
Everything else in flooring is sold by area. Carpet is sold by length off a fixed-width roll, and you pay for the full width whatever your room measures. That single fact drives every carpet estimate.
A 10 foot wide room takes 12 foot carpet, and the extra 2 feet is bought, paid for and thrown away. The same 12 foot roll in an 11 foot 6 inch room wastes only 6 inches. The room that costs the least per square foot is the one closest to just under the roll width — which is why 12 foot carpet exists at all, since most American bedrooms fall between 10 and 12 feet.
Running the carpet the other way round is worth checking. A 14 by 11 room takes 14 feet of 12 foot carpet one way and 11 feet the other, and the difference is real money. The calculator works out both orientations so you can see which direction runs cheaper before you commit.
Twelve feet is the dominant US width and where the choice of styles is widest. If a carpet you like comes only in 12 foot, that is normal.
Fifteen foot and 13 foot 6 inch are sold as wide goods, and they exist for exactly one reason: to cover a wide room without a seam. A 13 foot room in 12 foot carpet needs a seam; in 13 foot 6 inch it does not. Wide goods usually cost more per square yard and come in fewer styles, but on the right room they save both money and a visible join.
Six foot is mostly commercial, and useful for hallways and stairs where a wide roll would be almost entirely waste.
Any room wider than the roll needs a seam. Seams are normal and a good fitter makes them nearly invisible on a cut pile, but placement matters more than technique.
Run seams in the direction of the main light source, not across it. A seam running toward a window disappears; one running across the light catches a shadow line down its length forever.
Keep seams out of doorways and traffic paths. Every step across a seam works at it, and the one place a seam will eventually open is the place people walk. Push it toward the edge of the room or under where furniture sits.
Keep the pile direction consistent across a seam. Carpet has a nap, and two pieces joined with the pile running opposite ways look like two different colours regardless of how well the join is made.
The US carpet trade historically priced by the square yard and much of it still does, while flooring stores increasingly quote square feet. One square yard is 9 square feet, so a $27 per square yard carpet is $3 per square foot — the same number presented two ways, and an easy way to make one quote look far cheaper than another.
Get both quotes in the same unit before comparing. The calculator shows both figures for this reason.
Check what a quoted price includes. Carpet, padding, fitting, tack strip, furniture moving and old carpet disposal are sometimes bundled and sometimes each a separate line, and a low carpet price with everything itemised beneath it often lands higher than an all-in quote.
Padding is bought by the square foot or square yard of floor area, not off the carpet roll, so it has almost none of the width waste carpet does. Buy the room area plus a small allowance.
Density matters more than thickness. A dense 8 lb pad at 7/16 inch outlasts a soft, thick one and supports the carpet backing properly; too thick and soft a pad flexes under the carpet and breaks it down from below. Most residential carpet warranties specify a maximum pad thickness — usually 7/16 or 1/2 inch — and fitting a thicker one can void the warranty.
The estimate above covers carpet only. Padding, tack strip and fitting labour are all separate and worth pricing before deciding between two carpets.
strips = ceil(room width ÷ roll width)
roll length = strips × room length
you pay for = roll length × roll widthThe room is tried both ways round and the cheaper layout wins — turning a room 90° often drops a whole strip. A 13 ft × 24 ft room takes 312 sq ft of carpet laid one way and 576 sq ft laid the other, on the same roll.
Anything wider than the roll needs a seam. Seams are normal and a good installer hides them, but you should know before you order how many you're getting and roughly where they land.
This figure is the carpet itself. Padding, tack strip and fitting are quoted separately, and patterned carpet needs extra for matching the repeat — ask your supplier for the pattern repeat and add that to the length.
Broadloom carpet is traditionally sold by the square yard in the US and many suppliers still quote that way, though some now price per square foot. There are 9 square feet in a square yard, so carpet at $27 per square yard is $3 per square foot. This calculator shows both so you can compare quotes directly.
12 ft is the dominant US standard. 13 ft 6 in and 15 ft exist as wide goods but are stocked less widely, and 6 ft shows up mainly in commercial ranges and hallway runners. Metric equivalents are 3.66 m, 4 m and 5 m.
To avoid a seam in rooms that just miss 12 ft. A room 12 ft 6 in wide needs two strips and a seam on a 12 ft roll, but goes down in one piece on a 13 ft 6 in roll. If your room is between 12 and 13 ft 6 in, ask whether the carpet you like comes in the wider width before accepting a seam.
On a 12 ft roll, run the strips along the 12 ft side: one 12 ft wide strip 13 ft long gives you 156 sq ft with no seam. Run them the other way and you need two strips, 288 sq ft, and a seam. Same room, same roll, nearly double the carpet — which is why this calculator checks both orientations.
Because it is wider than the carpet roll in both directions. A 12 ft roll cannot cover a 14 ft wide room in one piece, so the installer joins strips. Seams are a normal part of carpet installation and a good installer makes them nearly invisible — but you should know how many you are getting before you order.
Run them in the same direction as the light from the main window, so the pile shading hides the join. Keep them out of doorways, entry sightlines and high-traffic paths, and never put one down the middle of a walkway or under dining chairs that slide. Under furniture and at door thresholds are the natural places to hide them. If the installer is also laying pad, its seams should run perpendicular to the carpet seams or be offset by at least 6 inches.
No. This is the carpet itself. Padding, tack strip, door bars and labour are quoted separately, and padding is priced per square foot of floor area rather than per roll length. Installers also trim a few inches off each strip, so treat the roll length as a minimum and let your supplier add their own allowance.
Patterned carpet needs extra length so the repeat lines up across seams and along walls. Ask your supplier for the pattern repeat measurement and add roughly one repeat per seam. Plain and textured carpets do not have this problem.