Tile Calculator
Calculate the number of tiles, grout joint volume, and total cost needed for floors or walls. Supports custom tile dimensions and waste factors.
Calculation Results
The overall square footage of the room.
Effective surface area of one tile including grout spacing.
Number of individual tiles required (rounded up, including waste).
Number of retail boxes of tiles to purchase.
How This Calculator Works
To use the tile calculator:
- Enter the length and width of the floor or wall area to be tiled.
- Enter the length and width of your selected tile (standard sizes include 12x12 inches, 18x18 inches, or 3x6 inch subway tiles).
- Select the grout joint width (typical size is 1/8 or 1/16 inch for thin grout lines).
- Specify the packaging count (so the calculator can estimate box purchases).
- Include a waste margin (10% is standard; use 15% if laying tiles in a diagonal or herringbone pattern).
Formula & Calculations
The total area of the floor is calculated first:
Room Area = Length × Width
Next, the effective area of a single tile is computed by adding the grout joint width to both tile dimensions:
Tile Area = (Tile Length + Grout spacing) × (Tile Width + Grout spacing)
Finally, the count of tiles is calculated, adding waste and rounding up:
Tiles = ceil((Room Area / Tile Area) × (1 + Waste / 100))
Step-by-Step Calculation Examples
Kitchen Floor (10ft x 12ft room)
Calculating requirements for 12x12 inch tiles with 1/8 inch grout joints, packed 10 to a box with 10% waste.
- length: 12
- width: 10
- tile_length: 12
- tile_width: 12
- grout_joint: 0.125
- box_qty: 10
- waste: 10
- area: 120.0 sq ft
- single_tile_area: 1.0209 sq ft
- tiles_needed: 130
- boxes_needed: 13
Frequently Asked Questions
Why do I need a waste margin for tile?
Tiling requires cutting tiles to fit along walls, corners, and around plumbing pipes. Cut tiles are often unusable, so buying an extra 10% ensures you do not run short mid-project.
How does grout joint width affect tile spacing?
Adding grout space increases the effective area of each tile, reducing the total count of tiles needed slightly over a large room. It is essential to include this spacing in the calculations.