Tile Calculator
A 10×12 ft bathroom floor needs 120 sq ft of tile. With 10% waste, that's 132 sq ft — about 132 tiles (12×12") or 9 boxes. Budget $400-1,200 for materials.
Tile Calculator
Enter your project dimensions for instant results.
You Need
—
How to Calculate Tile
The formula adjusts for grout joints and waste:
tiles_needed = (area_sqft / tile_sqft) × (1 + waste_factor)
Where tile_sqft includes the grout gap:
tile_sqft = ((tile_width_in + grout_in) × (tile_height_in + grout_in)) / 144
| Layout Pattern | Waste Factor | Tile Cuts |
|---|---|---|
| Straight / grid | 10% | Minimal — cuts at walls only |
| Brick / offset | 12% | Half-tiles at ends of offset rows |
| Diagonal (45°) | 15% | Triangular cuts at every wall |
| Herringbone | 15-20% | Complex angled cuts throughout |
| Mosaic / medallion | 20% | Custom cuts around design |
| Size | Sqft per tile | Common use |
|---|---|---|
| 4×4″ | 0.11 | Accent/backsplash |
| 6×6″ | 0.25 | Backsplash, small bath |
| 12×12″ | 1.00 | Floors, walls |
| 12×24″ | 2.00 | Modern floors, showers |
| 18×18″ | 2.25 | Large floors |
| 24×24″ | 4.00 | Open-concept floors |
Common Mistakes:
- Forgetting to subtract areas for vanities, toilets, and fixtures (measure and subtract these)
- Using the same waste factor for straight and diagonal layouts — diagonal wastes 50% more
- Not accounting for grout joints — 1/4" grout lines reduce effective coverage by 3-5%
- Ordering from multiple production lots — color shifts are subtle in the box but obvious on the floor
- Forgetting threshold and edge pieces — these require additional trim tiles or bullnose
Frequently Asked Questions
How many 12x12 tiles do I need for 100 square feet?
You need 110 tiles. Each 12×12" tile covers 1 square foot, so 100 sq ft = 100 tiles plus 10% waste = 110 tiles. If using diagonal layout, order 115 tiles (15% waste).
How much does it cost to tile a bathroom floor?
For a 50 sq ft bathroom floor, tile materials cost $150-750 depending on tile quality ($3-15/sqft). Professional installation adds $5-15/sqft. Total: $400-1,500 for a typical bathroom. Budget separately for backer board, thinset, and grout.
How do I account for grout lines in tile calculation?
Add the grout joint width to both tile dimensions before calculating coverage. For a 12×12" tile with 1/4" grout: (12.25 × 12.25) / 144 = 1.04 sqft effective size per tile. This small adjustment matters over large areas — it can mean 3-5 extra tiles per 100 sqft.
What tile size is best for a small bathroom?
12×24" tiles make small bathrooms look larger because fewer grout lines create a cleaner visual. Avoid tiles smaller than 6×6" on floors — excessive grout lines collect dirt. For shower walls, 4×12" or 3×12" subway tile is a classic choice.
Should I buy extra tiles beyond the waste factor?
Keep 2-3 extra tiles beyond your calculated total for future repairs. Tile production lots change, so matching an exact color years later is nearly impossible. Store spares flat in a dry location.
Related Tools
Square Footage Calculator
Calculate square footage for rooms, yards, and irregular shapes. Supports rectan
🪨Gravel Calculator
Calculate cubic yards and tons of gravel needed. Enter area and depth for drivew
🎨Paint Calculator
Calculate gallons of paint for walls and ceilings. Subtract doors and windows au
🖼️Wallpaper Calculator
Calculate wallpaper rolls for any room. Accounts for pattern repeat, doors, wind
🏗️Drywall Calculator
Calculate drywall sheets, joint compound, tape, and screws for any room. Account