Tile Calculator
What this calculator does
This calculator estimates the number of tiles and total square footage of tile needed to cover a floor, wall, backsplash, or other surface. It accounts for tile size, grout spacing, layout pattern, and a waste factor for cuts and breakage, so you can order the right amount of material the first time.
Tile installation is one of the most common home improvement projects—kitchens, bathrooms, entryways, patios, and showers all benefit from durable, attractive tile. But ordering too little means a mid-project scramble for matching tile (which may be from a different dye lot), and ordering too much wastes money. This calculator helps you find the right quantity with a built-in buffer.
Whether you are a DIY homeowner or a professional contractor, accurate tile estimation keeps projects on schedule and on budget.
How to use it
- Enter the area dimensions: length and width of the surface to tile (in feet or inches).
- Enter the tile size (e.g. 12" × 12", 6" × 24", 4" × 4").
- Enter the grout joint width (typical: 1/16" to 1/4").
- Enter a waste percentage (default: 10% for straight layouts, 15% for diagonal).
- Review the total area, tiles needed, and boxes to purchase (based on tiles per box).
Formulas used
Area to tile = Length × Width (subtract any permanent fixtures like cabinets or vanities if applicable)
Effective tile size (including grout): Tile + grout per dimension. Example: 12" tile + 1/8" grout = 12.125" effective. Effective area per tile = 12.125" × 12.125" = 147.02 sq in = 1.021 sq ft
Tiles needed = Total area / Effective area per tile
With waste factor: Adjusted tiles = Tiles needed × (1 + Waste % / 100) Example: 144 tiles × 1.10 = 159 tiles (rounded up).
Boxes needed = Adjusted tiles / Tiles per box (rounded up)
Examples
Example 1 — Kitchen floor (12×12 tile): Room = 10 × 14 ft = 140 sq ft. Tile = 12" × 12" (1 sq ft each with grout). Waste = 10%. Tiles = 140 × 1.10 = 154 tiles. At 12 tiles/box = 13 boxes.
Example 2 — Shower walls (6×6 subway tile): Three walls: total area = 80 sq ft. Tile = 6" × 6" (0.25 sq ft each). Waste = 10%. Tiles = (80 / 0.25) × 1.10 = 352 tiles.
Example 3 — Diagonal floor layout (large format): Room = 12 × 16 ft = 192 sq ft. Tile = 18" × 18". Waste = 15% (diagonal cuts). Tiles per sq ft = 1 / (18.125/12)² = 1 / 2.28 = 0.439 → 192 / 2.28 = 84.2 tiles × 1.15 = 97 tiles.
Tips and common mistakes
- Always add waste. 10% is the minimum for a straight (grid) layout. Use 15% for diagonal, herringbone, or other complex patterns. For small rooms with many cuts, consider 15–20%.
- Buy from the same dye lot. Tile color can vary between manufacturing batches. Order all your tile at once and check that box labels show the same lot number.
- Buy a few extra. Beyond the waste factor, keep 2–3 extra tiles for future repairs. A cracked tile years later is easy to replace if you have a matching spare.
- Account for grout joint width. Wider grout joints reduce the number of tiles needed slightly. Narrow joints (1/16") are common for rectified (precision-cut) tiles; wider joints (1/4") are typical for natural stone.
- Measure each wall separately for wall tile projects, as walls are rarely the exact same size. Do not assume symmetry.
- Large-format tiles in small rooms produce more waste from cuts. Consider whether a smaller tile would be more material-efficient (and often easier to install).