How to Calculate Tile for Stairs

Every step is made of two tiled surfaces: the tread (the horizontal part you step on) and the riser (the vertical face beneath the next tread). Measure each one, plus the overall stair width.

Typical residential dimensions are a tread run of 10″–11″ (250–280 mm), a riser rise of 7″ (180 mm), and a stair width of about 36″ (915 mm). Measure your own staircase in several spots — older stairs are rarely perfectly uniform, and you should size your cuts to the largest tread you find.

The front edge of every tread overhangs the riser below — this lip is the nosing. It needs a finished, rounded edge so it does not chip and so the step reads clearly underfoot. You finish it one of two ways:

Plan for the nosing overhang — usually 3/4″–1-1/4″ (20–32 mm) — when you size the tread piece, and budget one nosing or bullnose unit per step. Confirm your chosen tile line offers matching trim before you buy the field tile.

Add one tread area to one riser area for the area per step, then multiply by your number of steps. Here is a worked example for a 13-step staircase that is 36″ (915 mm) wide:

Convert inches to feet by dividing each dimension by 12 before multiplying, or divide the square-inch total by 144. If your staircase has a landing, measure it as a separate rectangle and add its area to the total.

Stairs need a higher waste factor than a flat floor because almost every tread and riser piece is cut to fit and the nosing involves precise trimming. Choose your factor based on layout complexity:

Slip resistance matters far more on stairs than on a flat floor — a slick tread is a fall hazard. Two ratings tell you how grippy a tile is when wet:

Favor textured or matte finishes over polished tile on treads, and consider a grooved stair-nosing trim for an added grip line at each step edge.

Tile is sold by the box, and every box lists its coverage in square feet. Divide your final square footage (base area plus waste) by that coverage, then round up to whole boxes.

Order your stair-nosing or bullnose pieces separately — they are usually sold by the linear foot or individually, not in the field-tile box. Buy one extra box of the same dye lot so repairs years from now still match.