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Tile Calculator

How many tiles do you need? Floor area, tile size and waste % — get the exact count plus boxes to buy.

Unit

Result —

About this calculator

Underestimating tile count is the most common DIY tile mistake. Cuts at edges, breakage during installation, future repairs — they all eat into your tile budget. This calculator gives you the precise tile count for any area including a standard waste allowance, plus the number of boxes if you know the per-box count.

How it works

Area divided by single-tile area gives the bare tile count. Multiply by (1 + waste %) to cover cuts and breakage. Then round up — you can't buy a fraction of a tile.

The standard waste allowance is 10 %. Bump it to 15 % for diagonal patterns (more cuts) or complex layouts with many cuts around fixtures. Drop to 7 % for straight grid in a simple rectangular room with experienced installation.

Box-count rounding matters: if tiles are sold in boxes of 12 and you need 50, you must buy 60 (5 boxes) — not 4 boxes plus 2 loose. Most stores won't break boxes.

Always order from a single batch (same dye lot). Colour variations between batches are subtle but visible on a finished floor. Keep 2–3 spare tiles after the project for future repairs.

Formula

tile_area_sqm = (tile_width_cm × tile_height_cm) / 10,000
exact_tiles   = floor_area_sqm / tile_area_sqm
tiles_to_buy  = ceil(exact_tiles × (1 + waste% / 100))
boxes_to_buy  = ceil(tiles_to_buy / tiles_per_box)

Examples

120 sq ft floor, 12×12-inch tiles, 10 % waste, no box constraint

Each 12×12 tile is 1 sq ft. 120 tiles cover the floor exactly, plus 12 for 10 % waste = 132 tiles total.

Result: 132 tiles

12 m² bathroom, 30×30 cm tiles, 15 % waste, 11 tiles/box

Tile area is 0.09 m², so 133 tiles cover the area exactly. Adding 15 % waste gives 154. At 11 tiles per box, that's 14 boxes (154 / 11).

Result: 154 tiles — 14 boxes

Frequently asked questions

What waste percentage should I use? +
10 % for standard grid layouts. 15 % for diagonal patterns, hexagonal tiles, or rooms with many cuts (around toilets, pipes, irregular walls). 5–7 % only for very simple rectangular rooms with experienced installation.
What about grout? +
This calculator gives tile count only. For grout, multiply the tile perimeter by depth and divide by the manufacturer's coverage rate — typically 0.5–1.5 kg per square metre depending on grout-line width.
Should I include trim or border tiles? +
Yes, but calculate them separately. Add the linear footage of borders (e.g. baseboards or wall-floor edges) and divide by the trim-tile length to get count. The main calculator handles only field tiles.
How do I handle small offcuts? +
Keep them in a labelled box for future repairs — they're free. Many installers reuse offcuts for cuts at other edges of the same room to reduce waste.
Why doesn't half a tile + half a tile = one tile in real installations? +
Cuts have to fall against the wall on one side. You can almost never re-use the offcut from one cut on another cut elsewhere without the colour orientation looking wrong. That's why waste % exists.

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