Floor Tile Calculator
Calculates exact tile piece and box counts for floor installations (12x12, 12x24, 24x24, or custom sizes) with pattern waste (straight, diagonal 45°, herringbone), plus thinset and grout requirements.
Formula
Tile Area (sq ft) = (Tile Length × Tile Width) ÷ 144; Boxes = Ceil((Room Sq Ft × (1 + Waste %)) ÷ Box Sq Ft)
1. Room Area = Length × Width 2. Single Tile Area (sq ft) = (Tile Length in × Tile Width in) ÷ 144 3. Total Area with Waste = Room Area × (1 + Waste %) 4. Total Tiles = Ceil(Total Area with Waste ÷ Single Tile Area) 5. Boxes = Ceil(Total Area with Waste ÷ Box Sq Ft) 6. Thinset (50 lb bags) = Ceil(Total Area with Waste ÷ 45 sq ft/bag) 7. Grout = Ceil(Total Area with Waste × 0.35 lbs/sq ft)
Inputs
- Room Length
- Room Width
- Tile Length (Inches)
- Tile Width (Inches)
- Square Feet Per Box
- Tile Layout Pattern
Worked example
Laying 12x24 inch porcelain tiles in 16 sq ft boxes with a standard 1/3 offset pattern and 10% waste.
Outcome: Room area is 120 sq ft. Adding 10% waste equals 132 sq ft. At 2 sq ft per tile, you need 66 tiles. Dividing 132 sq ft by 16 sq ft/box gives 8.25 boxes, rounding up to 9 full boxes (144 total sq ft). Thinset: 3 bags (50 lb). Grout: 1 bag (25 lb).
Why is a 1/3 offset recommended for 12x24 tiles instead of 50% brick pattern?
Large format tiles have a slight natural crown/bow in the center. A 33% maximum offset minimizes height differences (lippage) between adjacent tiles, whereas a 50% offset puts the highest peak directly next to the lowest end.