Tile Calculator

How it works

To estimate tiles needed for a floor, divide the floor area by the area of one tile, then add a waste percentage to cover cut waste, breakage, and irregular edges. This calculator handles square tiles (12-inch, 18-inch, 24-inch are common); rectangular tiles work the same way if you compute tile area as length × width in inches and convert to ft² (divide by 144).

For typical rectangular rooms with whole tiles, 10% waste covers cut tiles along the perimeter and the occasional break. For diagonal layouts (tiles laid at 45°), bump waste to 15-20%. For complex patterns (herringbone, basket weave) or rooms with many cuts (around vanities, toilets, irregular walls), 15-20% is safer.

Always buy from the same dye lot. Like paint, ceramic and porcelain tiles vary subtly batch-to-batch; running short and re-ordering can produce a visible color mismatch. Buy all tiles at once for the project plus a few extra for future repairs — a missing tile from a discontinued line is a problem.

Layout planning. Before installing, dry-fit a row across the room and measure the cut sizes at the walls. If the cut would be smaller than 1/3 of a tile, shift the starting line so both ends have a larger cut. For doorway transitions and prominent visible lines, plan to land on a full tile.

Underlayment and grout aren't included here. Cement backer board adds $1-3/ft²; thinset mortar adds $0.50-1/ft²; grout adds $20-30 per room. Total tile project cost is typically 2-4× the tile material cost when you include the substrate, adhesive, grout, and labor.

Tile sizes affect look and cut waste. Larger tiles (18", 24") look more contemporary, have less grout to clean, but produce more waste from cuts. Smaller tiles (4-6") are more forgiving on uneven floors and produce less cut waste but more grout lines.