Stair Flooring Calculator

How much flooring for stairs?

Each step gets a nosing on its front edge, one or two strips of board on the tread behind it and a strip on the riser, and each strip is cut from a board whose leftover is usually too short for anything else. That is why stairs take more material than their square metres suggest.

The calculator counts nosings, tread and riser strips and boards, adds 10% for breakages and mistakes, and joins the stair boards to the rest of the floor before rounding to packs — so a matching floor and staircase share packs. Use “Add stairs” in the laminate flooring calculator or the vinyl flooring calculator to do both at once.

How to measure a staircase

You need five measurements, all taken on the existing stairs:

The treads being covered and the risers — usually one more riser than treads.
Width: side to side, between the walls or strings.
Tread depth (going): from the riser to the front edge, including the existing nosing overhang.
Riser height: from one tread to the next.
A landing, if there is one; it is counted by area like a small floor.

The stair formula

nosings = ⌈E ÷ ⌊L_nosing ÷ W⌋⌉; strips = treads × rows_tread + risers × rows_riser; boards = ⌈strips ÷ ⌊L ÷ W⌋⌉

E is the number of nosed edges, W the stair width and L the board length. rows_tread comes from the tread depth less the nosing cover, divided into board widths; rows_riser from the riser height. Boards get 10% extra before rounding to packs, and adhesive is ⌈treads ÷ 2⌉ tubes.

Worked example

13 treads, 14 risers, 900 mm wide, treads 260 mm including the overhang, risers 180 mm; laminate 1380 × 193 mm, 8 per pack; nosings 1.2 m covering 75 mm.
Nosings: 13 + 1 = 14 edges, one 1.2 m nosing per 900 mm step → 14 nosings (or 7 of 2.4 m).
Tread field 260 − 75 = 185 mm → 1 strip cut to 185 mm; riser 180 mm → 1 strip. 27 strips, one per board → 27 boards; plus 10% → 30 → 4 packs (32 boards).
Adhesive: ⌈13 ÷ 2⌉ = 7 tubes. Stair area: 3.04 m² of treads + 2.27 m² of risers = 5.31 m².

Stair nosings: how many and what length

Every nosed edge needs a nosing: one per tread, plus one on the landing edge if the floor up there gets the same finish. Nosings come in lengths such as 1.2 m and 2.4 m; a 2.4 m piece covers two 900 mm steps, so 14 edges take 7 long nosings or 14 short ones. If the stairs are wider than a nosing, each one needs a joint, and the calculator says so.

Treads and risers from boards

Behind the nosing, the tread field is the tread depth less what the nosing covers, 75 mm by default. It is filled with rows of boards like a small floor, cut to width; a riser takes one or two strips. A strip uses a whole board when the stairs are wider than half a board, and two strips come from one board on narrower stairs. Grab adhesive is counted at one tube per two steps.

Tiling stairs

For tiles, the treads, risers and any landing are counted by area with 20% waste for the many small cuts, with adhesive and grout as in the tile calculator. A stair edge trim goes on every nosed edge, cut from 2.5 m lengths.

Frequently asked questions

How many stair nosings do I need?

One per tread, plus one for the landing edge if it gets the same flooring. A long nosing can cover two narrow steps: 2.4 m nosings on 900 mm stairs halve the count.

How many packs of laminate for 13 stairs?

For 900 mm wide stairs with 1380 × 193 mm boards, about 30 boards with 10% extra — 4 packs of 8 — plus 14 nosings of 1.2 m.

How many square metres is a staircase?

Treads × width × depth plus risers × width × height. Thirteen 900 × 260 mm treads and fourteen 180 mm risers come to 5.31 m² — but you buy by the piece, not by that area.

Do I count the top step?

Count every tread you cover. The landing edge is not a tread, but it usually gets a nosing; that is the “nosing on the landing edge too” option.

Can I use the same boards as the floor?

Yes, and with a matching nosing the stairs and the floor share packs: add the stairs next to your rooms and the project list rounds the boards together.

What about winders?

Winders and open sides with return nosings are not counted yet. Enter winders as straight steps at their widest depth and add a little extra.

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Last updated 19 October 2026

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