Tile Calculator
Calculate how many tiles and boxes you need for floors and walls.
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How to Calculate Tiles for Any Project
Whether you're tiling a bathroom floor, kitchen backsplash, or living room, the tile calculator gives you an accurate material estimate so you can buy the right amount. The key variables are area, tile size, and waste percentage.
The Basic Calculation
Area (sq ft) = length × width. Tiles per sq ft = 144 ÷ (tile width in inches × tile height in inches). A 12×12 tile: 144 ÷ 144 = 1 tile/sq ft. A 6×6 tile: 144 ÷ 36 = 4 tiles/sq ft. Multiply tiles per sq ft by total area to get your base count, then add waste percentage and divide by tiles per box to find how many boxes to buy.
Waste Percentages by Situation
10% for simple rectangular rooms with a straight-set (parallel to walls) pattern. 15% for rooms with obstacles like toilets, cabinets, or many corners. 20% for diagonal (45°) patterns — every edge cut is at an angle creating larger waste pieces. 20–25% for small mosaic tiles or intricate custom patterns.
Grout and Thinset
Thinset mortar (adhesive): about 50 lbs per 100 sq ft for floor tiles. Grout coverage depends on tile size and joint width. For 12×12 tiles with 3/16-inch joints: ~40–50 lbs per 100 sq ft. For 4×4 tiles with 1/8-inch joints: ~1 lb per sq ft. Always check the manufacturer's coverage chart.
Choosing Tile Size
Larger tiles (18×18, 24×24) minimize grout lines and look more contemporary. They require a very flat subfloor (less than 1/8 in deviation in 10 ft). Medium tiles (12×12) are the most versatile. Smaller tiles (4×4, 6×6) are more forgiving on uneven subfloors but require more grout and installation time.
Subfloor Preparation
Tile is a rigid material — it needs a solid, flat, non-flexing substrate. On wood subfloors, add a layer of cement backer board (1/4 to 1/2 inch) before tiling to prevent cracking from subfloor flex. Concrete subfloors are ideal. Fill any cracks or low spots with floor leveling compound before tiling.
Frequently Asked Questions
100 tiles base + 10% waste = 110 tiles. A 12×12 tile covers exactly 1 sq ft. If tiles come 10 per box, you need 11 boxes. Always buy whole boxes and round up.
10% for straight-lay rectangular rooms. 15% for rooms with obstacles. 20% for diagonal patterns. 25% for small mosaic tiles or complex shapes. When in doubt, use 15%.
Thinset (tile adhesive mortar) is the bonding layer between the subfloor/wall and the tile. It sets hard and bonds strongly. Use unmodified thinset under membrane systems; latex-modified thinset for most floor and wall applications. Don't substitute regular mortar or construction adhesive for thinset on tile.
Yes for cement-based grout (the most common type). Sealer prevents staining and makes cleaning easier. Apply sealer 48–72 hours after grouting and reapply every 1–2 years. Epoxy grout doesn't need sealing but is harder to apply.
Yes — shower tiling is a manageable DIY project with proper preparation. Key steps: install cement backer board, apply waterproofing membrane at seams and floor, use a shower-specific mortar, slope the floor toward the drain, and use epoxy or sanded grout. YouTube tutorials and tile manufacturer instructions are invaluable.