# Carpet calculator

> 14′ × 12′ room: 19.4 sq yd of carpet, 19.6 sq yd of pad and 13 pieces of tack strip, with the seams laid out. Tack strip, pad, seams and stretching — the full stretch-in install.

## What to buy (14′ × 12′ room)

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.

| Buy | Material | How StudSheet counts it | What it is for |
|---|---|---|---|
| **19.4 sq yd (174 sq ft)** | Carpet (12′ roll width, plain) | 1 piece 12′ wide × 14′ 6″ (the room’s length + 3″ 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. 12′ roll picked: least carpet (15′ roll: 1 piece, no seam, 20.9 sq yd). | Sold by the square yard or foot in 12 ft or 15 ft rolls. |
| **19.6 sq yd (177 sq ft)** | Carpet pad (cushion) (7/16″ 6-lb rebond) | 168 sq ft room + 5%. Pad is trimmed to the inside edge of the tack strip. | Goes under the carpet, inside the tack strip. |
| **13 strips** | Tack strip (“tackless strip”) (4 ft pieces) | 49′ of wall (doorways skipped) + 5% ÷ 4 ft per strip. Nail it ⅜″ or less from the wall, pins toward the wall. | The thin wood strip with angled pins that grips the carpet edge. Pins face the wall. |
| **1 box** | Staples ½″ (½″, for your stapler) | A staple every 6″ along the pad edge and pad seams. | For stapling carpet pad to wood. |
| **1 roll** | Duct tape (pad seams) (roll) | Tape the pad seams so they don’t shift. | Joins pad pieces. |
| **1 strip** | Carpet-to-hard-floor transition (36″) | One per doorway to a hard floor. | Metal or wood strip that finishes carpet at a doorway. |
| **1 pack + 1 roll** | Contractor bags + duct tape (heavy-duty) | Cut the old carpet into 3 ft strips, roll and tape. Check your town’s bulk pickup rules. | For rolling up and hauling the old carpet. |

### 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.

## The steps, in order

> **DIY OK: you can do this yourself with standard tools.** About 10–15 hours of work for this example.

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.

## Tools (18)

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

| Tool | Need | Why |
|---|---|---|
| **Knee kicker** | **Must have** | Hooks the carpet on the strip along each wall |
| **Carpet knife** | **Must have** | Heavy knife for cutting carpet from the back. |
| **Utility knife + blades** | **Must have** | Scores drywall and vinyl plank, trims pad. Swap blades often. |
| **Carpet wall trimmer** | **Must have** | Rides along the wall and trims carpet to the exact length for tucking. |
| **Stair tool (carpet tucker)** | **Must have** | Tucks the edge into the gully |
| **Framing hammer** | **Must have** | Nails tack strip |
| **Aviation snips** | **Must have** | Cuts tack strip |
| **Straightedge (6 ft)** | **Must have** | Dead-straight edge for cutting sheets and checking floor flatness. |
| **Chalk line** | **Must have** | Snaps a long straight line on floors, subfloors and ceilings. |
| **Tape measure (25 ft)** | **Must have** | The red boxes every 16″ on the blade are stud spacing. |
| **Knee pads** | **Must have** | Flooring and tile are all knees. |
| **Work gloves** | **Must have** | Tack strip pins bite |
| **Safety glasses** | **Must have** | Every cut, every nail, every time. |
| **Hammer tacker (staple gun)** | **Must have** | Staples carpet pad to a wood subfloor. |
| **Pry bar** | **Must have** | Pulls baseboards, old tack strip and flooring. |
| **Floor scraper** | **Must have** | Removes old pad, staples and adhesive. |
| **Power stretcher** | Rent | The carpet standard (CRI 105) makes it mandatory |
| **Shop vac** | Good to have | Drywall dust, grout, sawdust. |

## Mistakes and how the math works

### 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.

## Code, permits and safety

The Sheet sets its code notes for the job's state or province. These are New Jersey's and Ontario's; the [code reference](https://studsheet.com/codes) 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”.

## Questions

### 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](https://app.studsheet.com/p/carpet) 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.

## Ask about it

Stuck while you carpet a room? Ask in the [Carpet group](https://studsheet.com/forum/carpet) of the StudSheet community with this Sheet attached. Homeowners who've done it and verified pros answer, and anyone can read it.

## More flooring & tile Sheets

- **[Flooring for contractors](https://studsheet.com/trades/flooring)**: run this takeoff at your own prices, send the estimate, and get it signed and the deposit paid.
- **[Install vinyl plank flooring](https://studsheet.com/sheets/lvp)** (14′ × 12′ floor): Click-together LVP: boxes, trim, transitions and the gaps that matter.
- **[Tile a floor](https://studsheet.com/sheets/tile)** (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](https://studsheet.com/sheets/woodfloor)** (14′ × 12′ floor): Install solid or engineered hardwood or laminate, or sand and refinish an old wood floor.
- **[Tile a kitchen backsplash](https://studsheet.com/sheets/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](https://studsheet.com/sheets/shower)** (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](https://studsheet.com/sheets/carpetstairs)** (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](https://studsheet.com/sheets)**, across 16 trades.
- **[Code reference](https://studsheet.com/codes):** frost depths, guard heights, stairs, retaining walls.