Close-up of red carpet wrapped over the nosing of three stair steps

Stair runner and wall-to-wall

Stair carpet calculator

Carpet a staircase with a runner or wall to wall and get the length or square yards, pad, tack strip and staples. Each step is measured as tread plus riser plus the nosing the carpet wraps, and the 3D preview shows your color.

Enter the stairs

Stair runner calculator

Runner Wall to wall

The stairs

Count every riser (the vertical faces) from the floor up to the top landing: a flight always has one more riser than treads, and the top riser is carpeted too. Tread is the run, from the front edge of one nosing to the front edge of the next, not the whole board. Riser is the height of one step. Nosing is how far the board overhangs past the riser, counted once; if you measure the whole board as the tread, set the nosing to 0.

Stepssteps Tread depthin Riser heightin Nosingin Stair widthin Runner widthin

Measure the stair width between the walls or strings. In runner mode it only sets the wood margin each side (and the 3D preview), and the runner must be narrower than the stair.

Install style Roll width Winder (pie) stepssteps Bullnose first step
The bottom step curves out past the strings, so it is cut as one wider piece.

Waterfall is the usual install. Hollywood adds about 1 in a step for the tuck under the nosing and needs tack strip on the treads only. Winder steps are wedge-shaped: each is cut separately, measured at its wide outer edge. Winders are part of the step count, not on top of it.

Landings

Add a landing only if it is carpeted with the stairs. A runner follows the landing's depth; wall-to-wall carpet covers its whole area.

Carpet, pad and look

Waste Carpet color #7D6A5A Include carpet pad
Off for a runner by default, since many runners go over a thin pad or none; on for wall to wall, which needs a pad. Sized per CRI 105: on each tread and over the nose, riser bare. Stair rods
Brass rods, one in each crease (one per riser), shown in the 3D preview.

Optional

What will it cost?

Every material the calculator worked out gets its own price. Each field starts at a typical US figure so you have something to work from — change any of them to what your own supplier charges.

These prices are approximate. They are national US retail figures, and what you actually pay varies with your region, your supplier, the season and how much you buy at once. Treat them as a starting point, not a quote — always price the job from your own supplier's current figures before you order.

Your prices

Stair runner per linear foot USD Typical $5–$60 Broadloom carpet per square yard USD Typical $13.50–$63.00 Carpet pad per square yard USD Typical $2.70–$10.80 Tack strip per linear foot USD Typical $0.07–$0.30

Add an installed cost estimate
Adds a labor band of $15–$60 per step

The rest of the floor

A room is rarely one material and nothing else. The measurements you have entered here carry straight across to the floor next door, and to the pad under both.

Tools for the job

What makes this job easier

Tools and materials that suit this kind of job. These are affiliate links: if you buy through one, Renovimo may earn a commission at no extra cost to you. It never changes the figures on this page.

Garvee Stair-climbing hand truck, 330 lb Carries the roll of carpet or runner and the pad up to the top landing in one trip; a 12 ft roll is heavy and awkward on a stair. Check price

Garvee Tool bag, 17 in Keeps the stair tool, knee kicker, stapler, utility knife and tape in one place, up the flight with you. Check price

Garvee Putty knife set, 1–5 in A stiff blade tucks the carpet edge into the gap against the wall and the riser crease before the last staples go in. Check price

Garvee 20V cordless hammer drill Drills the pilot holes for stair rod brackets in the riser and the wall, and the anchors for a new handrail. Check price

Garvee Stair handrail, 6 ft A new carpeted flight is the time to fit or replace the handrail; the carpet should not be tucked under it. Check price

Plastic Place Contractor bags, 42 gal, 3 mil Bags torn-out carpet, pad and staples as you go, so nothing stays on the stairs to trip over. Check price

Not the tool you were after? Browse the whole range at Garvee or Plastic Place — the stores these picks come from.

Staple gun with a yellow handle and loose staples on dark wood boards

Based on your result

What you'll need

Quantities update after every calculation. Order the runner or carpet in one piece from one dye lot, and add the pad only if you ticked it.

Carpet or runner Amazon: Runner by the foot, or wall to wall cut from the roll, waste included; Calculate above
Carpet pad Amazon: Stair-grade pad on each tread and over the nose, riser bare; —
Tack strip Amazon: Wall to wall: each tread, plus each riser for a waterfall install; —
Staples Amazon: 1/2 to 9/16 in staples, boxes of 1 250; —
Stair tool and knee kicker Amazon: Tucks and stretches the carpet into each crease; one each
Stair rods Amazon: Optional, one per riser crease, with brackets; —

As an Amazon Associate I earn from qualifying purchases.

The maths

Stair carpet calculator: how the length is counted

Carpet follows the stair like a ribbon: along each tread, over the nosing and down the riser. One step uses tread plus riser plus nosing; multiply by the number of steps, add waste, and convert.

one step = tread + riser + nosing (+ 1 in for Hollywood)
runner (ft) = ⌈ (steps × step + landing depths) × (1 + waste) ÷ 12 ⌉
pieces across the roll = ⌊ roll width ÷ stair width ⌋
roll length = ⌈ ⌈ steps ÷ pieces across ⌉ × step × (1 + waste) ÷ 12 ⌉ ft
carpet billed (sq yd) = roll width × roll length ÷ 9
pad per step = tread + nosing + 2 in · tack strip = steps × width × 2 (waterfall) or × 1 (Hollywood)

For a whole room of carpet use the carpet calculator; pad thickness and density are in the carpet pad guide.

01
Count the steps and measure one
Count the risers from the floor to the top landing. Measure the tread depth, the riser height and how far the tread overhangs, on a middle step: the first and last are often different.
02
Add the nosing
The carpet wraps over the edge, so each step needs tread + riser + nosing. A 10 in tread, 7.5 in riser and 1 in nosing is 18.5 in of carpet a step.
03
Add the landings
A runner continues across a landing by its depth; wall-to-wall carpet is cut for the landing's width times its depth from the same roll.
04
Add waste and convert
10 percent covers the cuts and the extra at the top and bottom step. 13 steps of 18.5 in is 240.5 in; with 10 percent that is 264.55 in, 22.05 ft, so you buy 23 ft of runner. Wall-to-wall carpet is cut one piece per step with the pile running down the stair (CRI 105 section 11.3), so a 36 in stair gets 4 pieces across a 12 ft roll: 4 rows of 18.5 in, 74 in, 81.4 in with waste, so 7 ft of roll, billed as 12 ft x 7 ft / 9 = 9.4 sq yd.
05
Size pad, tack strip and staples
Under the carpet the pad goes on each tread and over the nose, about tread + nosing + 2 in a step, and the riser stays bare (CRI 105 section 11.2). Wall-to-wall carpet is gripped by tack strip on every tread, and on every riser too for a waterfall install; a Hollywood install needs the treads only. A runner is stapled, about every 3 in in two rows a step, with 1/2 to 9/16 in staples.

Runner or wall to wall

How much carpet for stairs?

A straight flight of 13 steps with a 10 in tread, 7.5 in riser and 1 in nosing takes about 23 ft of runner, or 7.4 sq yd of net wall-to-wall carpet 36 in wide with 10 percent waste. Carpet is bought off the roll, though: cut one piece per step from a 12 ft roll, 7 ft of it, billed as 9.4 sq yd. A 36 × 36 in landing is another row cut from the roll and takes the buy to 11 ft, 14.7 sq yd.

A runner is narrower than the stair and leaves 4 to 6 in of wood showing each side, with the edges bound in a darker or matching tape. Wall-to-wall carpet covers the full width and is stretched over a pad. Runners are usually quicker to fit and less carpet to buy; wall-to-wall is quieter and warmer underfoot. For rooms, see the carpet calculator, and for thickness and density of the pad underneath the carpet pad guide.

Stair dimensions matter to safety as well as to carpet. The US residential code (IRC R311.7.5) allows a riser of 7¾ in at most and a tread of at least 10 in; the calculator shows a note when your numbers are outside that.

Good to know

Stair carpet questions, answered

Count the risers and multiply by tread plus riser plus nosing, add 10 percent for waste, and divide by 12. Thirteen steps of 10 in tread, 7.5 in riser and 1 in nosing is 23 ft of runner.

Measure the tread run (nosing edge to nosing edge), the riser height and the nosing overhang on a middle step. Measure the width at the narrowest point. Count the risers up to the top landing, and add each landing you will carpet.

Many runners go over a thin pad or none, so this page leaves it off for a runner and on for wall to wall. Pad cushions the step and lengthens the life of the carpet; tick the box to price it.

Most are 26 to 32 in wide, leaving 4 to 6 in of the tread showing each side of a 36 in stair. Keep at least 2 in (5 cm) bare each side, and centre it so the margins match.

A staple about every 3 in across the carpet, in a row at the back of each tread and one under the nosing, 1/2 to 9/16 in long so they go through the backing and the pad. A box of 1 250 covers a runner up a normal flight.

By the foot from a roll in whole feet, usually 26 to 32 in wide, or as ready-made rugs in 8, 10, 12 and 14 ft lengths. A rug is a fixed length, so the page shows the shortest standard rug that covers your flight, and the joins you would need if the flight is longer than 14 ft. Rugs are hard to join invisibly on a stair, so measure for cut-to-length when you can.

A waterfall install carries the carpet straight over each nosing and down the riser, with tack strip on the treads and the risers. Hollywood (cap and band) tucks the carpet under the nosing, takes about 1 in more per step, and needs tack strip on the treads only.