How to Measure Stairs for Flooring

Updated 2026-07-19

Stairs are where flooring estimates go to die. A first-timer measures the bedroom perfectly, buys exactly enough LVP, then looks at the staircase and guesses — and guesses are why installers keep an extra box in the truck.

Stairs are not hard to measure, but they are different: every step is two surfaces, the cuts are unforgiving, and no two staircases in the same house are guaranteed to match. Here is the method, step by step.

Know the anatomy: tread, riser, nosing

The tread is the flat part your foot lands on — typically 10 to 11 inches deep. The riser is the vertical face between steps, usually 7 to 7.5 inches tall. The nosing is the rounded front edge of the tread, which finished floors handle with a dedicated stair-nose molding rather than a wrapped plank.

1. Interior stair width is 36 inches in most homes; older houses run 30-34 inches.
2. A straight flight for an 8-foot ceiling usually has 12-14 steps — count yours, do not assume.
3. Any step that looks wider or shaped differently — winders, a flared bottom step — gets measured on its own.

The per-step math

Measure one step, then multiply by the count. A 36-inch-wide stair with a 10-inch tread: the tread is 360 square inches, or 2.5 square feet. The 7-inch riser is 252 square inches, or 1.75 square feet. Covering both faces takes about 4.25 square feet per step. You will hear a rule of thumb of roughly 3 square feet per step — that only holds on narrower stairs or tread-only coverage, which is exactly how rules of thumb leave you short on stairs.

Covering treads only — the usual approach for LVP and laminate finished with stair-nose trim — that same step needs just 2.5 square feet of plank.

Count steps, then measure the odd ones

Count every step from the first riser to the top landing. Thirteen steps at 4.25 square feet comes to 55.25 square feet of material for a fully covered stair — call it 56. Tread-only LVP on the same flight: 13 × 2.5 = 32.5 square feet.

Winders and pie-shaped steps on a turn are measured individually: take the tread at its widest point and treat each one as its own rectangle. A flared or bullnose bottom step can eat double the material of a standard step.

Landings are easy — do not skip them

A landing is just a small room. A 36 × 36 landing is 9 square feet; a 3 × 6 landing at a turn is 18. Add every landing to the stair total before waste ever enters the conversation. If the top landing runs straight into a hallway getting the same floor, measure the hallway separately and add it to the upstairs room total, not the stair total.

Waste on stairs: 15% minimum

Stairs generate more scrap per square foot than any other part of the house: every tread is a cut piece, pattern and grain matching across steps eats material, and a miscut tread is a full loss. Add 15% to the stair total — 20% on hardwood if you want grain flowing up the flight. The 56-square-foot example: 56 × 1.15 = 64.4, so you are buying for 65 square feet. Pros order a tread or two beyond even that; a spare in the attic beats a discontinued pattern when a step gets gouged five years from now.

Order the trim with the plank

Stair-nose molding and any riser material are bought separately from field plank — nose pieces are sold by the linear foot, one per step, and they are the part everyone forgets. Once you have per-step area, step count, and landings totaled with waste, run the numbers through the flooring calculator to confirm the box count before you order anything.