Tile Calculator

Tiling a floor or wall requires calculating the exact area to cover, adding waste for cuts and breakage, and then converting that into a tile quantity and materials cost.

Formula: Area to Tile = Length × Width (for rectangular rooms) Tiles Needed = Area ÷ Tile Area × (1 + Waste Factor) Tile Area = Tile Length × Tile Width Total Cost = Tiles Needed × Price per Tile + Adhesive Cost + Grout Cost

What each variable means:

• Area to Tile — total square footage or square meters of the surface being tiled. Subtract fixed fixtures (toilets, vanities) if applicable.
• Waste Factor — extra tiles ordered to account for cuts at edges, corners, and breakage. Standard recommendation: 10% for straight lay, 15% for diagonal lay, 20% for complex patterns.
• Tile Area — a 12×12 inch tile = 1 sq ft; a 30×60 cm tile = 0.18 m².
• Grout coverage — one 25 lb bag of sanded grout covers approximately 50–70 sq ft depending on joint width and tile size.
• Adhesive coverage — one 50 lb bag of thin-set mortar covers approximately 40–50 sq ft.

Standard tile sizes and use cases:

• 12×12 in (30×30 cm) — bathroom floors, small kitchens
• 18×18 in (45×45 cm) — living rooms, larger spaces
• 24×24 in (60×60 cm) — large open-plan areas
• 3×6 in subway tile — backsplashes, shower walls
• 4×16 in plank tile — modern wood-look floors

Worked example: Bathroom floor: 8 ft × 10 ft = 80 sq ft. Using 12×12 inch tiles ($2.50 each). Waste factor 10%. Tiles needed = 80 × 1.10 = 88 tiles Cost = 88 × $2.50 = $220 in tiles Add ~$35 for thin-set mortar and ~$20 for grout = Total ≈ $275

Always buy 10–15% extra and keep leftover tiles — future repairs require matching tiles, and discontinued styles are impossible to match later.