About this tool
Tile Calculator is a free, in-browser tool that counts the tiles a floor or wall needs, including the grout line between them and a waste allowance for cuts and breakage. Enter the room size in feet, the tile dimensions and grout gap in inches, and it returns the tile count and, optionally, the number of boxes. Nothing is uploaded.
The room area is converted to square inches: (length × 12) × (width × 12). Each tile's footprint including grout is (tile width + gap) × (tile height + gap) square inches. Tiles = ceil(room area ÷ tile footprint × (1 + waste ÷ 100)), rounded up. If you enter tiles per box, boxes = ceil(tiles ÷ per box), also rounded up.
Use the 10% default waste for a straight layout; increase it to 15% or more for diagonal patterns or rooms with many cuts. Buying whole boxes at once ensures your tiles share the same production batch and shade.
Frequently asked questions
How does the grout gap change the count?
Each tile effectively occupies its own size plus one grout line in each direction, so the tool adds the gap to both tile dimensions before dividing the room area. A wider gap means slightly fewer tiles.
How much waste should I add?
Ten percent is the usual allowance for a standard straight layout with some cuts. Bump it to 15–20% for diagonal or herringbone patterns, small rooms or large-format tiles, where more tiles get cut.
Why round the tile and box counts up?
You cannot buy a fraction of a tile or a partial box, and running short mid-job risks a batch with a different shade. Rounding up, plus the waste allowance, keeps a small reserve for future repairs.
Does the tool send my measurements anywhere?
No. Room and tile dimensions and the resulting counts are computed in your browser and never uploaded; the calculator works offline.
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