# Stair carpet calculator

> 13 steps, 3′ wide: 12 sq yd of carpet, 4.2 sq yd of pad and 20 pieces of tack strip, cut step by step. Carpet, pad and tack strip cut step by step — waterfall or wrapped (Hollywood) — with the pile running down the stairs and the landing included.

## What to buy (13 steps, 3′ wide)

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 |
|---|---|---|---|
| **12 sq yd (108 sq ft)** | Carpet (12′ roll, cut 9′ long) | 14 pieces (13 steps + 1 spare), each 37″ wide × 19-1/2″ long (tread 10-1/2″ + riser 7-1/2″ + 1-1/2″ for the nose and the tuck), 3 across the 12′ roll: 5 rows = 97-1/2″, rounded up to 9′ — stores cut by the foot. The pile runs along the roll, down the stairs. | Sold by the square yard or foot in 12 ft or 15 ft rolls. |
| **4.2 sq yd (38 sq ft)** | Carpet pad (cushion) (7/16″, 8-lb rebond or denser) | 13 treads × (10-1/2″ + 1″ over the nose) × 34″ = 35.3 sq ft + 5%. Stairs want a firm pad: soft pad lets the nose wear through. | Goes under the carpet, inside the tack strip. |
| **20 strips** | Tack strip (“tackless strip”) (4 ft pieces) | 13 steps × 2 runs (the tread and the riser) × 35″ = 75.8 ft + 5%, in 4 ft pieces. | The thin wood strip with angled pins that grips the carpet edge. Pins face the wall. |
| **1 box** | Staples ½″ (½″, for your stapler) | ≈296 staples: every 4″ around each pad piece. About 1,250 to a box. | For stapling carpet pad to wood. |
| **1 pack + 1 roll** | Contractor bags + duct tape (heavy-duty) | Roll the old carpet and pad into bundles and tape them. Check your town’s bulk pickup rules. | For rolling up and hauling the old carpet. |

### In Canada (13 steps, 914 mm wide)

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:

- **10.0 m², Carpet:** 14 pieces (13 steps + 1 spare), each 940 mm wide × 495 mm long (tread 267 mm + riser 191 mm + 38 mm for the nose and the tuck), 3 across the 3.66 m roll: 5 rows = 2.48 m, rounded up to 2.74 m — stores cut it in steps of 0.3 m. The pile runs along the roll, down the stairs.
- **3.5 m², Carpet pad (cushion):** 13 treads × (267 mm + 25 mm over the nose) × 864 mm = 3.3 m² + 5%. Stairs want a firm pad: soft pad lets the nose wear through.
- **20 strips, Tack strip (“tackless strip”):** 13 steps × 2 runs (the tread and the riser) × 889 mm = 23.11 m + 5%, in 1.22 m pieces.
- **1 box, Staples 13 mm:** ≈296 staples: every 102 mm around each pad piece. About 1,250 to a box.
- **1 pack + 1 roll, Contractor bags + duct tape:** Roll the old carpet and pad into bundles and tape them. Check your town’s bulk pickup rules.

## The steps, in order

> **DIY OK: you can do this yourself with standard tools.** About 5–8 hours of work for this example.

1. Pull the old carpet, pad and tack strip; pull every staple; fix squeaky treads with screws now.
2. Measure each step (they vary): the tread, the riser and the nose allowance, and the width at the back and the front.
3. Tack strip: on each tread ½″ from the riser, pins toward the riser; on each riser 1″ above the tread, pins down.
4. Pad: cut each piece to cover the tread and wrap the nose, staple it tight, and trim it at the tack strip — never over it.
5. Cut the step pieces from the roll with the pile running down the stairs (rub your hand down the carpet: it should feel smooth).
6. Install from the bottom up: hook each piece on the strip, kick it into the tread strip, tuck the crotch with the stair tool, then let it fall from the nose to the next crotch.
7. Top step: carpet ends under the floor transition at the top; check every step is tight before anyone uses the stairs.

## Tools (16)

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

| Tool | Need | Why |
|---|---|---|
| **Stair tool (carpet tucker)** | **Must have** | Tucks the carpet tight into the crotch of each step |
| **Knee kicker** | **Must have** | Stretches each piece onto the tack strip |
| **Carpet knife** | **Must have** | Cuts the pieces; snap off a dull blade often |
| **Hammer tacker (staple gun)** | **Must have** | Staples the pad to the treads |
| **Framing hammer** | **Must have** | Nails the tack strip |
| **Aviation snips** | **Must have** | Cuts tack strip |
| **Utility knife + blades** | **Must have** | Scores drywall and vinyl plank, trims pad. Swap blades often. |
| **Straightedge (6 ft)** | **Must have** | A straight cut along the roll |
| **Tape measure (25 ft)** | **Must have** | The red boxes every 16″ on the blade are stud spacing. |
| **Chalk line** | Good to have | Marks the pile direction and the cut lines on the back of the roll |
| **Knee pads** | **Must have** | Every step is done on your knees |
| **Work gloves** | **Must have** | Tack strip pins bite |
| **Safety glasses** | **Must have** | Every cut, every nail, every time. |
| **Pry bar** | **Must have** | Pulls the old tack strip |
| **Locking pliers** | Good to have | Pulls the old staples |
| **Shop vac** | Good to have | Drywall dust, grout, sawdust. |

## Mistakes and how the math works

### Mistakes that cost a callback or a second trip

- **Pile running up the stairs:** It wears faster and looks a different color. The pile runs down the stairs: mark an arrow on the back of the roll.
- **Cutting all the pieces from one measurement:** Steps vary by a little: measure each one before you cut its piece.
- **Pad that stops short of the nose:** The nose wears through first. Wrap the pad over it and staple it tight.
- **Staples in the walking surface:** Staple in the crotch and under the nose, never on top of the tread.
- **Seams on the tread:** A seam belongs in the crotch, where it hides and doesn’t wear.

### What the calculator assumes

- A waterfall piece is the tread + the riser + 1½″ (the nose and the tuck); a wrapped (Hollywood) piece + 3″ to wrap under the nose. Pieces are 1″ wider than the stair (½″ to trim each side), 6″ more per open side for the return. Typical installer allowances.
- Pieces are cut across the roll, as many as fit side by side, in rows along it: the pile runs down the stairs. One spare piece; a winder takes two. The length is rounded up to the foot, the way stores cut it.
- Pad: each tread + 1″ over the nose, 2″ narrower than the carpet, + 5%. Tack strip: one run on each tread and one on each riser, + 5%.
- The stair itself (its nosing, its handrail) is the Inside stairs Sheet’s job; the room at the top or bottom is the Carpet Sheet’s.

## 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.

- **Tight carpet is safe carpet:** Loose carpet on stairs is a fall hazard: kick every piece tight into the tack strip, and keep people off the stairs until each step is done.
- **Carpet makes each nosing deeper:** Carpet and pad add about ½″ to the front of each tread. Stair nosings should stay ¾–1¼″ when the tread is under 11″ (IRC R311.7.5.3; R318.7 in the 2024 IRC): if your nosings are already near the limit, ask before you carpet.
- **No permit needed:** Carpeting stairs is ordinary maintenance in New Jersey (N.J.A.C. 5:23-2.7(c)(1)(ix)): no construction permit.

## Questions

### What materials do I need to carpet stairs?

For the worked example, a 13 steps, 3′ wide, the Sheet counts 5 lines with waste included, starting with carpet (12 sq yd (108 sq ft)), carpet pad (cushion) (4.2 sq yd (38 sq ft)), tack strip (“tackless strip”) (20 strips), staples ½″ (1 box). Each line's math is in the table above. Put in your own sizes in the [stair carpet calculator](https://app.studsheet.com/p/carpetstairs) and every line is counted again.

### How long does it take to carpet stairs, and can I do it myself?

About 5 to 8 hours for the worked example, in 7 steps. StudSheet stamps it **DIY OK**: you can do this.

### What tools do I need to carpet stairs?

16 in all. The must-haves start with stair tool (carpet tucker), knee kicker, carpet knife, hammer tacker (staple gun), framing hammer, aviation snips. On the Sheet you mark each one as owned, to buy or to rent.

## Ask about it

Stuck while you carpet stairs? 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.

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