Count tiles for a floor or wall from the area and tile size — including the grout gap in each tile's effective area, a layout waste factor and boxes. Runs entirely in your browser — your numbers never leave this device.
Effective tile area includes one grout gap on each tile, so larger gaps mean slightly fewer tiles. Keep spare tiles from the same batch for future repairs — dye lots vary.
| Layout | Typical waste |
|---|---|
| Straight | 10% |
| Offset / brick | 10–15% |
| Diagonal | 15% |
| Herringbone | 20% |
Tiles are counted, not measured out by area alone, and the count turns on the effective tile area: each tile occupies its own dimensions plus one grout gap, because every tile in the grid carries a joint on two sides. A 12×12 in tile with a 1/8 in gap therefore covers 12.125 × 12.125 in — 1.021 ft², not exactly 1 ft² — and across a whole floor that difference removes several tiles from a naive area division. Ignoring the gap is the most common reason tile counts come out high.
The raw count is then increased by a waste factor for cuts, breakage and pattern matching, and the factor belongs to the layout: a straight grid wastes about 10%, offset and brick layouts 10–15%, diagonal layouts about 15% because every edge tile is cut on the bias, and herringbone about 20%. The table prints those typical factors so the choice is explicit. Finally the tile count is divided by the tiles per box and rounded up, because tiles are bought by the box.
Every rounding in this chain goes up, deliberately: tiles are discrete, a part tile at an edge still consumes a whole tile, and running one tile short at the end of a job costs more than a spare box. Keep the spares — a tile from the same batch is the only reliable replacement for a future crack, and batches vary in shade.
Because each tile in the laid grid takes up its own size plus a joint. At a 1/8 in gap on 12 in tiles the effective area is 1.021 ft² per tile, so a 100 ft² floor needs about 98 tiles before waste, not 100. Wider gaps on smaller tiles move the count further.
The layout decides it: about 10% for a straight grid, 10–15% for offset, 15% for diagonal and 20% for herringbone, per the table on this page. Rooms with many corners, niches or cuts around fittings belong at the top of their layout's range.
Because a replacement tile bought later will almost certainly come from a different production batch, and batches differ slightly in shade and size. The rounded-up boxes from this estimate double as the matching spares for future repairs.
No. This calculator counts tiles and boxes from area, tile size, gap and waste. Adhesive and grout are sold by coverage that depends on trowel notch size and joint width and depth, which are separate estimates.
No. The calculation runs entirely in the browser and nothing entered is uploaded, stored or tracked.
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