Tile Calculator
Estimate how many tiles you need for a rectangular room, with optional box counts from carton coverage.
How to use
Enter room size, individual tile size, and waste. Optionally add coverage per box from the carton to estimate boxes.
How the calculation works
Room area is adjusted for waste, then divided by one tile’s area and rounded up. Box count uses the same adjusted area when coverage is provided.
Formula
project_area_ft² = length_ft × width_ft; tile_area_ft² = tile_length_ft × tile_width_ft; adjusted = project_area × (1 + waste%/100); tiles = ceil(adjusted ÷ tile_area); boxes = ceil(adjusted ÷ coverage_per_box) when coverage > 0
Example calculation
A 10 ft × 12 ft room is 120 ft². With 10% waste → 132 ft². 12 in × 12 in tiles are 1 ft² each → 132 tiles. If a box covers 10 ft² → 14 boxes.
Assumptions
Room shape
Single rectangle
Material: tile · Key: geometry
Add multiple rectangles for L-shaped rooms.
Source: Geometric model
Box coverage (ft² / box)
User-entered (no universal default)
Material: tile · Key: box_coverage
Not hard-coded — product cartons differ widely.
Source: Planning default — confirm with your product label or supplier quote. Not a lab or manufacturer certification.
Grout joints
Not subtracted from tile area
Material: tile · Key: grout
Tile count uses full tile face area; layout and grout change real needs.
Source: Model limitation
Practical notes
- Buy extra for breakage and future repairs when the line may be discontinued.
- Diagonals and complex patterns usually need more waste than a straight layout.
- Always verify carton coverage on the box label.
Limitations
- Does not optimize cut layouts or account for niche/shower curbs in detail.
- Grout joint width is not modeled.
- Planning estimate only.
FAQ
- Do I have to enter coverage per box?
- No. Leave it blank (or zero) to get tile count only. Enter carton coverage when you want a box estimate.
- What waste percent should I use?
- Many straight layouts use about 10%. Diagonals and busy cuts often need more.
Related calculators
Results are planning estimates. See the Calculator Disclaimer.