Tile calculator and flooring guide
Tile counts, boxes, and waste.
This category currently has one live tool: the tile calculator. Use it for rooms, hallways, backsplashes, and showers when you know the floor or wall size and the tile size. Enter the room in feet and the tile in inches. The page gives square feet, tiles to cover, tiles to buy after waste, and boxes from the tiles-per-box number on your carton. If you are pouring a mud bed or a concrete slab under the tile, switch to the concrete calculator for that layer only.
US tile is sold by the square foot and by the box. The box label lists coverage and tiles per box; use that count, not a generic 10. Waste is 10 percent for a straight grid and 15 percent for diagonal or herringbone. Showers and small bathrooms with many cuts belong on the 15 percent side even on a straight layout. This calculator does not subtract grout joints; for 12 × 12 tile a ⅛ inch joint is about 2 percent of the area, which assumes a full 12 inch tile face. Waste already covers that for ordering.
Common mistakes: measuring a rug instead of the room; using the nominal 12 × 12 size when the face is 11 ¾ inches; forgetting a second rectangle for an alcove; rounding boxes down; mixing dye lots. Buy every box from the same lot, blend tiles from several boxes while you set, and keep one spare box from that lot for later repairs.