Tile Calculator
Find the number of floor or wall tiles and boxes to buy, accounting for grout joints and cutting waste.
How to use the Tile Calculator
- Enter the area length and pick its unit.
- Enter the area width and pick its unit.
- Enter the tile length and pick its unit.
- Enter the tile width and pick its unit.
- Enter the grout joint width and pick its unit.
- Enter the waste allowance – 10% for straight lay, 15% for diagonal or herringbone.
- Enter the tiles per box.
- Enter the price per tile.
- Press Calculate. The result updates automatically as you type, and you can switch the result unit at any time.
About the Tile Calculator
Use this calculator for floors, shower walls and backsplashes. For a wall, enter its width and height as length and width and subtract windows separately. Order all tiles from the same production lot (shade/caliber number on the box) so color and size match.
Straight layouts usually need 10% extra for cuts and breakage; diagonal, herringbone and large-format tiles need 15–20%. Keep a few spare tiles after the job for future repairs, since discontinued styles are hard to match.
Formula
Tile footprint = (Tile length + joint) × (Tile width + joint)
Tiles = Area ÷ Tile footprint × (1 + waste %), rounded up
Including the grout joint in the footprint matters for small tiles: 12 × 12 in tiles with ⅛-in joints occupy 12⅛ × 12⅛ in each, so slightly fewer tiles are needed than the bare tile size suggests.
Example calculation
Using the default values:
- Area length = 12 ft
- Area width = 10 ft
- Tile length = 12 in
- Tile width = 12 in
- Grout joint width = 1/8 in
- Waste allowance = 10%
the calculator returns:
- Tiles needed: 130 tiles
- Area to tile: 120 ft²
- Tiles per sq ft: 0.979
Frequently asked questions
How many 12 × 12 tiles do I need for 100 sq ft?
About 100 tiles, or 110 with a 10% waste allowance. Each 12-inch tile covers one square foot.
How much extra tile should I buy?
Buy 10% extra for a straight lay and 15–20% for diagonal or herringbone patterns, large tiles, or rooms with many corners.
What grout joint width should I use?
Rectified porcelain is often set with 1/16–1/8 in joints, standard ceramic floor tile with 1/8–1/4 in, and rustic or handmade tile with 1/4–1/2 in.
Last updated: · Category: Construction calculators