Stair 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 (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.

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.

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

• 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.

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.

• 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.

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 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.

Stuck while you carpet stairs? 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.
• Carpet a room (14′ × 12′ room): Tack strip, pad, seams and stretching — the full stretch-in install.
• 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.
• All 45 Sheets, across 16 trades.
• Code reference: frost depths, guard heights, stairs, retaining walls.