Tile Calculator
Tiles = (area × waste factor) ÷ tile area
How Tile Quantity Calculations Work
Tile count starts with the total area to cover in square feet, then divides by the effective area of one tile including grout lines. Convert tile dimensions from inches to feet: a 12 in × 12 in tile is 1 ft × 1 ft = 1 sq ft. With a 1/8 in grout gap (0.0104 ft), effective size becomes (1 + 0.0104)² ≈ 1.021 sq ft per tile.
For a 12 ft × 12 ft bathroom floor (144 sq ft) using 12×12 tiles with 1/8 in grout and 10% waste: adjusted area = 144 × 1.10 = 158.4 sq ft. Tiles needed = 158.4 ÷ 1.021 ≈ 156 tiles. Always round up — buying 155 when you need 156 means a trip to the store mid-project. Patterns like herringbone or diagonal layouts increase waste to 15–20%.
Rectangular tiles follow the same logic. A 6 in × 24 in plank tile covers 0.5 ft × 2 ft = 1 sq ft per piece (plus grout). Mosaic sheets are counted by sheet coverage printed on the box. Wall tile calculations use the same area math — measure each wall section, subtract tub surrounds and niches, then sum totals.
Grout joint width affects both tile count and grout bag quantity. Wider joints (3/16–1/4 in) suit rustic or handmade tile; narrow joints (1/16 in) suit rectified porcelain. Underlayment, thinset, and backer board are separate from tile count — budget one 50 lb thinset bag per 100–150 sq ft and cement board by the sheet (32 sq ft per 4×8 sheet).
| Floor Area | Tile Size | Tiles (10% waste) |
|---|---|---|
| 100 sq ft | 12×12 in | ~109 tiles |
| 144 sq ft | 12×12 in | ~156 tiles |
| 144 sq ft | 6×24 in | ~158 tiles |
| 200 sq ft | 18×18 in | ~89 tiles |
Enter your area, tile dimensions, grout gap, and waste percentage to get an accurate tile count. Use the square footage calculator first if you only have room dimensions.
Examples
| Example | Result |
|---|---|
| 144 sq ft floor, 12×12 tile, 1/8 in grout, 10% waste | ~156 tiles |
| 100 sq ft, 12×12 tile, 10% waste | ~109 tiles |
| 80 sq ft shower walls, 6×6 tile, 15% waste | ~350 tiles |
| 200 sq ft kitchen, 18×18 tile, 10% waste | ~89 tiles |
| 50 sq ft backsplash, 3×6 subway, 10% waste | ~440 tiles |
| 120 sq ft, 6×24 plank, 12% waste | ~134 tiles |
| 60 sq ft bathroom, 12×24 tile, 10% waste | ~33 tiles |
Frequently asked questions
Add 10% waste for straight layouts on simple rectangular floors. Diagonal, herringbone, or intricate patterns need 15–20% extra for cuts and breakage.
Wider grout joints slightly increase the effective size of each tile position, meaning fewer tiles per square foot. This calculator adds grout gap to tile dimensions automatically.
Yes. Calculate the wall area in square feet the same way as floors, subtract openings, and enter tile size and waste percentage.