Tile Calculator
Calculate the number of tiles needed for floors and walls.
About the Tile Calculator
The Tile Calculator estimates the number of tiles needed to cover a rectangular floor. Enter the floor dimensions, the tile dimensions, a waste allowance, and the layout pattern — the tool returns the number of tiles, accounting for cuts and breakage, plus the number of boxes to order.
The base calculation is simple: tiles = ceil(floor_area / tile_area). The complications come from real-world cutting waste: tiles at the edges of the room must be cut to fit, the offcuts cannot always be reused, and some tiles break during installation. A 10% waste allowance is standard for grid (straight-lay) patterns; 15% for brick (offset) patterns; 15-20% for diagonal (45-degree) patterns, which produce more unusable triangular offcuts.
Tile sizes vary widely. Common formats include 30x30 cm (about 12x12 inches, the classic floor tile), 60x60 cm (24x24 inches, large-format modern), 10x10 cm (4x4 inches, mosaics), 15x60 cm (6x24 inches, wood-plank look), and 60x120 cm (24x48 inches, oversized). Larger tiles cover more area per tile but produce more waste per cut — a 60x120 tile cut to fit a 5cm gap leaves a 5x120 offcut that may not be reusable.
Pattern choice affects waste. Grid (straight lay) is the most efficient, with all tiles aligned. Brick (offset by half a tile) requires more cuts at the edges. Diagonal (45 degrees) is the most wasteful, as every edge tile becomes a triangular cut. Herringbone, chevron, and Versailles patterns are even more wasteful but are not modeled here — consult the manufacturer’s coverage chart for those.
How It Works
The calculator first computes the floor area length * width and the tile area tile_l * tile_w. The number of tiles without waste is ceil(floor_area / tile_area) — rounded up because you cannot buy a fractional tile.
The waste multiplier is 1 + waste/100. With a 10% allowance, the multiplier is 1.10. The number of tiles with waste is ceil(tiles_no_waste * waste_multiplier).
The pattern adds an additional waste factor: 0% for grid, 5% for brick, 10% for diagonal. The total tiles to buy is ceil(tiles_no_waste * (1 + pattern_waste) * waste_multiplier).
The number of boxes assumes 10 tiles per box — this is a typical default for 30x30 cm floor tiles, but check the actual box count for your specific product. Large-format tiles (60x60 cm) often come in boxes of 4-6; mosaic sheets come in boxes of 10-12 sheets. Override the calculation by computing total_tiles / tiles_per_box for your specific product.
Edge cases: zero dimensions are rejected. A waste allowance above 50% is rejected (likely a typo). The pattern waste is added on top of the user-set waste allowance, so a 10% user allowance with a diagonal pattern gives 21% total waste (1.10 * 1.10 = 1.21).
The conversion to inches uses 1 m = 39.3701 inches; square inches use 1 m² = 1550.0031 in². The cost estimate uses $2/tile as a placeholder; replace with your actual tile price.
Worked Examples
Default: 5x4m floor, 30x30cm tiles, 10% waste, grid pattern. Floor: 20 m². Tile: 0.09 m². Tiles no waste: ceil(20 / 0.09) = 223. Tiles with waste: ceil(223 * 1.10) = 246. Tiles to buy: 246 (25 boxes). A standard bathroom or kitchen floor.
3x3m bathroom, 60x60cm tiles, 15% waste, brick pattern. Floor: 9 m². Tile: 0.36 m². No waste: ceil(9 / 0.36) = 25. With waste: ceil(25 * 1.05 * 1.15) = 31. Large-format tiles minimize grout lines but produce more waste per cut.
4x3m kitchen, 15x60cm wood-look tiles, 12% waste, brick pattern (the natural choice for plank tiles). Floor: 12 m². Tile: 0.09 m². No waste: 134. With waste: ceil(134 * 1.05 * 1.12) = 158.
5x5m living room, 30x30cm tiles, 20% waste, diagonal pattern. Floor: 25 m². Tile: 0.09. No waste: 278. With waste: ceil(278 * 1.10 * 1.20) = 367. Diagonal layout adds significant waste due to triangular edge cuts.
2x2m shower floor, 5x5cm mosaic, 15% waste, grid. Floor: 4 m². Tile: 0.0025. No waste: 1600. With waste: ceil(1600 * 1.15) = 1840. Mosaics are usually sold by the sheet (typically 30x30cm, 36 tiles per sheet); adjust the box calculation accordingly.
When to Use This Tool
- Estimating tile quantity for a bathroom, kitchen, or hallway floor before visiting the tile showroom.
- Comparing the cost per square meter of different tile sizes (small tiles are cheaper per tile but more labor-intensive to install).
- Deciding between grid, brick, and diagonal layouts based on the waste trade-off.
- Calculating tile needs for a backsplash or accent wall (treat the wall as the ‘floor’ and enter its dimensions).
- Planning a mosaic installation where tiles are tiny and per-box counts differ.
- Verifying a contractor’s tile quantity quote against the area-based estimate.
- Ordering spare tiles for future repairs — buy 5-10% extra beyond the calculated waste allowance for long-term matching.
Limitations & Disclaimer
The calculator assumes a rectangular floor with rectangular tiles and uniform layout. Non-rectangular rooms require manual area calculation. Herringbone, chevron, Versailles, and other complex patterns are not modeled — consult the tile manufacturer’s coverage chart. The default 10 tiles per box is a common figure for 30x30 cm floor tiles; check the actual box count for your specific product. Grout width, tile spacing, and substrate porosity are not modeled. The waste allowance is a guideline — actual waste depends on installer skill, tile fragility, and room geometry. See our disclaimer for full terms.
Frequently Asked Questions
Why is the waste allowance 10% by default?
10% is the industry-standard allowance for grid (straight-lay) tile installation, sufficient to cover edge cuts, breakage during shipping and installation, and minor miscalculations. For diagonal patterns, increase to 15-20%. For complex layouts like herringbone or Versailles, consult the tile manufacturer’s coverage chart. Buying too little means a mid-job shortage and a possible color-match issue with the next batch.
How does pattern affect waste?
Grid (straight lay) is the most efficient — all tiles aligned, edge cuts are simple rectangles. Brick (offset by half a tile) requires more edge cuts because the offset means alternating rows have different cut positions. Diagonal (45 degrees) is the most wasteful because every edge tile becomes a triangular cut, and triangular offcuts cannot be reused. Herringbone, chevron, and Versailles are even more wasteful but not modeled here.
How do I calculate tiles for a non-rectangular room?
Break the room into rectangles, calculate each separately, and sum. For an L-shaped room: <code>(length1 * width1) + (length2 * width2)</code>. For a room with a notch or bay window, subtract the notch area from the main rectangle. For circular or curved walls, approximate with multiple narrow rectangles.
What about wall tiles vs. floor tiles?
The calculation is the same; just use the wall dimensions (height times length minus doors and windows). For a typical bathtub surround (1.5m wide x 2.2m high), the area is 3.3 m². Subtract 1.6 m² for the bathtub opening, leaving 1.7 m² to tile. Use 15% waste for vertical installations (more cuts around fixtures).
How many tiles come in a box?
It varies by tile size and manufacturer. Common defaults: 30x30 cm floor tiles — 10 per box; 60x60 cm — 4-6 per box; 10x10 cm mosaics — 12 sheets per box. Check the product listing for the actual count. The calculator assumes 10 per box; adjust the box calculation by dividing the total tiles by the actual count.
Should I buy extra tiles for future repairs?
Yes — buy 5-10% extra beyond the calculated waste allowance, and store them in their original packaging in a dry location. Tile manufacturers discontinue product lines every few years, and even ‘the same’ tile from a different batch will have a slightly different color or texture. Having spares ensures you can replace cracked tiles without redoing the whole floor.
Last updated: September 9, 2026 · Author: HT99 Tools Editorial Team