Enter your room and tile dimensions to instantly calculate the tiles and boxes needed.
How the Tile Calculator Works
Enter Room Length & Width
Enter Individual Tile Size
Divide Room Area by Tile Area
Add Waste % & Convert to Boxes
What is a Tile Calculator?
A Tile Calculator estimates how many individual tiles and full boxes you need to cover a floor or wall, based on the room's dimensions and your chosen tile size. Tiles are typically sold by the box rather than individually, so this calculator converts your exact tile count into a practical, ready-to-purchase number of boxes — including a waste allowance for cuts, breakage, and pattern layout.
The Tile Calculation Formula
Room Area (ft²) = Room Length × Room Width
Tiles Needed = (Room Area ÷ Tile Area) × (1 + Waste %)
Tile area is calculated from your tile's length and width (typically given in inches, which the calculator converts to square feet). The result is then divided by tiles-per-box to determine exactly how many full boxes to purchase.
Recommended Waste Allowance by Layout
| Tile Layout Pattern | Recommended Waste % |
|---|---|
| Simple grid (straight lay) | 10% |
| Diagonal layout | 15% |
| Herringbone or complex pattern | 15 – 20% |
| Room with many corners/obstacles | 15% |
| Large, simple rectangular room | 7 – 10% |
Common Tile Sizes
- 12" x 12": A classic, versatile size for floors and walls.
- 18" x 18" or 24" x 24": Larger format tiles, popular for modern living areas, with fewer grout lines.
- 12" x 24": Popular rectangular "plank" style, often used to mimic wood flooring.
- 4" x 4" or mosaic sheets: Common for backsplashes and bathroom accent walls.
Tips for Tile Installation Planning
- Always buy extra: Keep leftover tiles for future repairs, since matching discontinued tile styles later can be difficult or impossible.
- Account for the layout pattern: Diagonal and complex patterns generate more cut waste than a simple straight layout.
- Measure the actual usable area: Subtract areas covered by built-in cabinetry or fixtures that won't need tile.
- Verify tiles are from the same dye lot: Natural stone and some ceramic tiles can vary slightly in color between production batches.
Frequently Asked Questions
How much extra tile should I buy?
A 10% waste allowance works well for simple layouts, while more complex patterns like diagonal or herringbone typically need 15-20% extra.
Why does my supplier round up to full boxes?
Most tile is sold in sealed boxes containing a fixed number of tiles, so even if you need only a few more tiles than a full box provides, you'll typically need to purchase the entire next box.
Should I include the doorway/threshold area?
Yes, include any area that will be tiled, including thresholds, unless you're specifically transitioning to a different flooring material at that point.
Does grout line width affect the calculation?
Grout line width has a relatively minor effect on tile count for most standard layouts, though very wide grout lines on small tiles can slightly reduce the number of tiles needed to cover the same area.