How Much Tile Do I Need?
The basic formula is: Area (sq ft) × waste factor ÷ tile area = tiles needed. For a 10×12 room with 12×12-inch tiles and 10% waste: 120 × 1.10 ÷ 1.0 = 132 tiles. Divide by tiles per box and always round up.
Waste Factor by Layout Pattern
| Pattern | Recommended Waste | Notes |
|---|---|---|
| Straight / grid | 10% | Easiest layout, fewest cuts |
| Offset / brick | 10% | Half-tile offsets on each row |
| Diagonal (45°) | 15% | Corner cuts increase waste significantly |
| Herringbone | 15% | Many 45° cuts at joints |
| Complex / mosaic | 20% | Multiple cuts, borders, inlays |
| Irregular room | +5% | Add extra for alcoves and bump-outs |
Frequently Asked Questions
How many tiles do I need for a 10×10 room?+
A 10×10 room is 100 sq ft. Using 12×12 tiles with 10% waste, you need 110 tiles — about 14 boxes of 8 tiles each. For 18×18 tiles, you need about 49 tiles (each covers 2.25 sq ft), or around 7 boxes of 7.
How much waste should I add for tile?+
Add 10% for straight-lay patterns, 15% for diagonal or herringbone layouts, and 20% for complex patterns or rooms with lots of cuts. For rooms with multiple angles or many alcoves, add an extra 5%.
How do I calculate tiles for a bathroom floor?+
Measure length × width in feet to get square footage. Add 10–15% for waste, then divide by the area of one tile. Our calculator handles all the math. For an average 5×8 bathroom, expect about 45–50 tiles at 12×12.
How many square feet does a box of tile cover?+
Coverage depends on tile size and count per box. A box of 6 tiles at 12×12 covers 6 sq ft. A box of 4 tiles at 18×18 covers 4.5 sq ft. A box of 3 tiles at 24×24 covers 12 sq ft. Always check the box label.