Carpet Calculator
Your room
Carpet to order
20.67 sq yd
- Layout
- 1 strip along the 15 ft length, 15.5 ft each
- Seams
- 0
- Floor area
- 180 sq ft (20 sq yd)
- Waste
- 3.3%
- Other direction
- 33.33 sq yd
- Pad
- 20 sq yd
- Tack strip
- 51 linear ft
Full-width strips, nap all one way. Ask your installer before ordering — they may piece a closet from offcuts.
Tools the pros use for this job
Knee Pads
NoCry Clear Safety Glasses for Men and Women with Anti-Fog and Scratch Resistant Wrap Around Lenses, Adjustable Temples and Nose Pads — ANSI Z87 Certified Protective Eyewear with 100% UV Shielding
$13.99
Check price on AmazonStretching and trimming carpet is all kneeling.
Chalk Line
Snap the seam line before you cut the second strip.
Transition Strip
Finishes the doorway where carpet meets a hard floor.
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Prices as of Oct 2, 2026, 4:36 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Carpet for common room sizes (12 ft roll)
| Room | Floor | Carpet to order | Seams |
|---|---|---|---|
| 10 × 10 ft | 11.11 sq yd | 14 sq yd | 0 |
| 12 × 10 ft | 13.33 sq yd | 14 sq yd | 0 |
| 12 × 12 ft | 16 sq yd | 16.67 sq yd | 0 |
| 14 × 12 ft | 18.67 sq yd | 19.33 sq yd | 0 |
| 15 × 12 ft | 20 sq yd | 20.67 sq yd | 0 |
| 16 × 14 ft | 24.89 sq yd | 38.67 sq yd | 1 |
| 20 × 14 ft | 31.11 sq yd | 38.67 sq yd | 1 |
| 24 × 16 ft | 42.67 sq yd | 44 sq yd | 1 |
Full-width strips with 3 in trim at each end, laid the cheaper way. An installer may piece offcuts into a closet or a narrow fill strip and order a little less.
Seams, nap and roll width
The standard roll width is 12 ft, so any room wider than 12 ft in both directions gets a seam. Installers put seams in low-traffic areas — not in doorways or hallways — and every piece has to run with its nap in the same direction, which is why an offcut can't simply be turned sideways to fill a gap. Some styles are also made in wider rolls; pick 13.5 or 15 ft above if the carpet you're pricing comes that way, since a room just over 12 ft wide may then need no seam at all.
Comparing with hard flooring? The carpet tile calculator counts carpet squares, which waste far less in odd-shaped rooms, and the square footage calculator adds up L-shaped rooms first.
Do this math on the job site — in the free app
Smart Tile Calculator for Android: offline, in your pocket, free.
How this calculator works
Strips. Strips across the room = ceil(room width ÷ roll width). Each strip runs the full length plus a trim allowance at both ends (3 in by default). Seams = strips − 1.
Square yards. Carpet to order = strips × strip length × roll width ÷ 9. The calculator works it with the strips running each way and keeps the smaller order.
Pad and tack strip. Pad covers the floor area (sq ft ÷ 9). Tack strip runs the perimeter, less the doorways.
Worked example. A 15 × 12 ft bedroom is 180 sq ft, 20 sq yd. Strips run along the 15 ft length: one 12 ft strip, 15 ft 6 in long = 186 sq ft = 20.67 sq yd, no seam. Run them the other way and the room needs two strips, 25 linear ft, 33.33 sq yd. A 20 × 14 ft room is the opposite: two strips along the 14 ft width (29 linear ft, 38.67 sq yd) beat two along the length (54.67 sq yd).
Frequently asked questions
How do I calculate how much carpet I need?
Divide the room width by the roll width (12 ft) and round up for the number of strips, multiply by the room length plus a few inches of trim, then multiply by 12 and divide by 9 for square yards. A 15 × 12 ft room takes one strip 15 ft 6 in long: 20.67 sq yd.
How many square yards of carpet do I need for a 12 × 12 room?
The floor is 16 sq yd (144 ÷ 9). With one 12 ft strip and 3 in trim at each end you order 12.5 × 12 ÷ 9 = 16.67 sq yd, with no seam.
Why do I have to buy more carpet than my room's square footage?
Because carpet comes off a 12 ft roll in full-width strips. A 14 ft wide room needs two strips, so you pay for 24 ft of width to cover 14 ft — the calculator lays the strips the shorter way to keep that waste down.
How do I convert square feet to square yards for carpet?
Divide by 9. 180 sq ft is 20 sq yd; 300 sq ft is 33.33 sq yd. Carpet and pad are priced per square yard, so price × square yards is the material cost.
How much carpet pad and tack strip do I need?
Pad covers the floor area only — a 15 × 12 ft room needs 20 sq yd. Tack strip runs the perimeter less the doorways: 54 ft minus one 36 in door is 51 ft.
Related calculators
- Floor Tile CalculatorTiles and boxes for any floor, by room dimensions and tile size.
- Flooring Square Footage CalculatorAdd rooms, L-shapes and circles for one running square-foot total.
- Carpet Tile Calculator24x24, 18x18 and 39x39 carpet squares plus boxes.
- Vinyl Tile & LVP CalculatorLVT, vinyl plank and peel-and-stick boxes by coverage.
Guides worth reading next
- How to Measure a Room for Tile (Step by Step)Measure any room for floor or wall tile: handle closets and alcoves, convert inches to decimals, subtract fixtures, and add the right waste percentage.
- Choosing the Right Tile Size for Your RoomHow tile size changes a room: when 12×24 beats 4×4, why small rooms can take large tile, grout line math, and the flatness rule for big formats.
- Sanded vs Unsanded vs Epoxy Grout: Which One Do You Need?Grout types explained by joint width and location: when sand scratches tile, why epoxy wins in showers, and how much of each type a bag actually covers.