How many tiles you need
Tile count is tiles = ceil(area ÷ tile size × (1 + waste%)). For 120 sq ft using 1 sq ft tiles with 10% waste you need 132 tiles. Always round up to whole tiles. Measure the surface first with the square footage calculator.
How to use this calculator
Enter floor or wall area, the tile size in square feet, and a waste percentage. The result rounds up and adds the waste cushion. Mortar and grout coverage are separate; the concrete calculator covers slab volume. For plank and sheet materials, the flooring calculator is the better fit.
Choosing waste
Use about 10% for straight layouts and 15% for diagonal or herringbone patterns and small rooms with many cuts. Keep spares for future repairs. Painting the surrounding walls? See the paint calculator.
Plan the layout before you buy. Setting out from a centreline usually leaves a balanced cut tile at each wall, while starting tight against one wall can leave an ugly sliver on the far side that is hard to cut cleanly. Large-format tiles need a flatter substrate and produce bigger offcuts, so lean towards the higher waste figure with anything over 12 inches. Grout and mortar are bought separately, and their coverage depends on tile size and joint width. Dry-lay a row first to confirm the cut sizes before any mortar goes down.
Frequently asked questions
- How do I calculate tiles needed?
- Divide the area by the tile size, round up, then add a waste percentage of about 10–15%.
- How much waste should I add?
- About 10% for straight layouts and 15% for diagonal patterns or rooms with many cuts.
- Should I keep extra tiles?
- Yes — keep a few spares from the same batch in case you need future repairs and dye lots change.
- What tile size do I enter?
- Enter the coverage of one tile in square feet — a 12 × 12 inch tile is 1 sq ft.
- How do I convert tile size in inches to square feet?
- Multiply the two dimensions in inches and divide by 144. A 12 by 24 inch tile is 288 divided by 144, or 2 square feet per tile.