Carpet calculator

Every line shows the quantity to buy and how StudSheet got it: the spacing, the waste and the package size, so you can check it before the supply house or the quote.

In Canada (4.27 m × 3.66 m room)

Set to Canada, the Sheet works the job out again for Ontario: metric sizes, bag sizes, the frost depth and the code notes. It doesn't just convert feet to meters. The first lines:

• 16.2 m², Carpet: 1 piece 3.66 m wide × 4.42 m (the room’s length + 76 mm at each wall), run along the length because that gives the fewest seams (none) for the least carpet. 3% ends up as offcut. No seams. 3.66 m roll picked: least carpet (4.57 m roll: 1 piece, no seam, 17.5 m²).
• 16.4 m², Carpet pad (cushion): 15.6 m² room + 5%. Pad is trimmed to the inside edge of the tack strip.
• 13 strips, Tack strip (“tackless strip”): 14.94 m of wall (doorways skipped) + 5% ÷ 1.22 m per strip. Nail it 10 mm or less from the wall, pins toward the wall.
• 1 box, Staples 13 mm: A staple every 152 mm along the pad edge and pad seams.
• 1 roll, Duct tape (pad seams): Tape the pad seams so they don’t shift.
• 1 strip, Carpet-to-hard-floor transition: One per doorway to a hard floor.

1. Pull the old carpet and pad; pull staples. Keep tack strip that’s solid with sharp pins.
2. Screw down squeaky subfloor to the joists.
3. Nail tack strip around the room: a gap from the wall of slightly less than the carpet’s thickness (max ⅜″), pins angled toward the wall. Skip doorways.
4. Lay pad, staple it along the inside edge of the strip, and trim it flush — never over the strip. Tape the seams.
5. Rough-cut carpet with 3″ extra at every wall.
6. Position the carpet with the pile running the same way everywhere.
7. Hook one corner with the knee kicker, then power-stretch toward the far walls.
8. Trim with the wall trimmer, tuck into the gully with the stair tool. Install transitions; cut out vents.

Must-have tools first, then the ones that help and the ones to rent for the day.

Mistakes that cost a callback or a second trip

• Pad over the tack strip: The pins can’t grab the carpet backing and the edge pulls loose. Trim pad to the strip’s inside edge.
• Stretching with only a knee kicker: Ripples within months. The carpet install standard (CRI 105) makes a power stretcher mandatory.
• Seams in the wrong place: Seams across a doorway or across the traffic path fray and show. Run them with traffic, and not across the light from the main window.

What the calculator assumes

• Full-width pieces run in the direction with the fewest seams, then the least carpet; +3″ at each end for trimming.
• No fill pieces (a pro may piece fills to save carpet; the pile direction must stay the same).
• Tack strip in 4 ft pieces around the room, minus 36″ per doorway, +5%.
• CRI 105 (the carpet installation standard): power stretcher mandatory; gully slightly less than the carpet thickness, max ⅜″; pad trimmed flush with the strip; seams parallel to traffic and not across natural light.
• Plain carpet. Patterns need extra for matching.

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the code reference has more. Always confirm with your building department.

• Get an install quote before renting tools: Stores often quote carpet installation. Compare it with renting a power stretcher and seaming iron.
• 12′ roll: least carpet: The Sheet picked the roll width. 12′ roll: 1 piece, no seam, 19.4 sq yd. 15′ roll: 1 piece, no seam, 20.9 sq yd. Change it under “Carpet roll width”.
• 3.66 m roll: least carpet: The Sheet picked the roll width. 3.66 m roll: 1 piece, no seam, 16.2 m². 4.57 m roll: 1 piece, no seam, 17.5 m². Change it under “Carpet roll width”.

What materials do I need to carpet a room?

For the worked example, a 14′ × 12′ room, the Sheet counts 7 lines with waste included, starting with carpet (19.4 sq yd (174 sq ft)), carpet pad (cushion) (19.6 sq yd (177 sq ft)), tack strip (“tackless strip”) (13 strips), staples ½″ (1 box). Each line's math is in the table above. Put in your own sizes in the carpet a room calculator and every line is counted again.

How long does it take to carpet a room, and can I do it myself?

About 10 to 15 hours for the worked example, in 8 steps. StudSheet stamps it DIY OK: you can do this.

What tools do I need to carpet a room?

18 in all. The must-haves start with knee kicker, carpet knife, utility knife + blades, carpet wall trimmer, stair tool (carpet tucker), framing hammer. On the Sheet you mark each one as owned, to buy or to rent.

Stuck while you carpet a room? Ask in the Carpet group of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

• Flooring for contractors: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
• Install vinyl plank flooring (14′ × 12′ floor): Click-together LVP: boxes, trim, transitions and the gaps that matter.
• Tile a floor (8′ × 5′ bathroom): Backer, thinset, tile and grout sized to your tile — bathroom, kitchen or entry, with the toilet reset when there is one.
• Hardwood and laminate floors (14′ × 12′ floor): Install solid or engineered hardwood or laminate, or sand and refinish an old wood floor.
• Tile a kitchen backsplash (12′ of backsplash, 18″ tall): Tile, adhesive, grout, edge trim and outlet extenders for the wall between the counter and the cabinets, counted from the run and height.
• Tile a shower or tub surround (5′ tub surround, tiled to 7′): Backer board, waterproofing, tile, thinset and grout for a tub surround or a walk-in shower — every seam, corner and pipe sealed.
• Carpet stairs (13 steps, 3′ wide): Carpet, pad and tack strip cut step by step — waterfall or wrapped (Hollywood) — with the pile running down the stairs and the landing included.
• All 45 Sheets, across 16 trades.
• Code reference: frost depths, guard heights, stairs, retaining walls.