InteriorCalc

Tile Calculator

Last updated: 2026-06-25

TL;DR

Tiles needed = ⌈(installation area ÷ area of one tile) × (1 + waste rate)⌉. Area of one tile = (width mm ÷ 1000) × (height mm ÷ 1000).

Example) Area 20 m², 300×300 tile (0.09 m²), 10% waste: 20 ÷ 0.09 × 1.1 = 244.4 → rounded up to 245 tiles.

Enter installation details

m²
Total floor or wall area to be tiled. 1 m² ≈ 10.76 sq ft.
mm
Width of one tile.
mm
Height of one tile.
%
Straight 10%, diagonal/herringbone 15-20%.
tiles
Enter this to also get the number of boxes.

Results are a reference estimate based on actual tile dimensions. Quantities vary with the layout pattern and wall/floor shape, so buy with extra.

How to use

  1. Enter area — Enter the floor or wall installation area to be tiled in square meters (m²).
  2. Enter tile size and waste rate — Enter the width and height of one tile (mm) and a waste rate (default 10%) for cutting and breakage.
  3. View the result — Click calculate to see the area of one tile, the number of tiles needed including waste, and the estimated number of boxes.

How to calculate tile quantity

The number of tiles is found by dividing the installation area by the area of one tile to get a base count, then adding the waste rate lost to cutting and breakage and rounding up. The area of one tile is the width (mm) and height (mm) each converted to meters and multiplied.

Area of one tile and tiles per m² by size (may vary)
Tile sizeArea of one tileTiles per m²
300 × 3000.09 m²about 11.1
300 × 6000.18 m²about 5.6
600 × 6000.36 m²about 2.8
200 × 2000.04 m²about 25
100 × 1000.01 m²about 100

Waste rate depends on the layout pattern. A grid (straight) layout is fine at 10%, but diagonal or herringbone patterns with lots of edge cutting need 15-20%. Area and waste rate concepts are covered in the guide to estimating interior material quantities.

Frequently Asked Questions (FAQ)

What tile waste rate should I use?

For straight (grid) layouts use 10%; for diagonal (45°) or herringbone patterns that require a lot of cutting use 15-20%. Tiles break during installation and many are cut at edges, so without extra you can easily run short. The default is 10%.

How do I calculate the area of one tile?

Area of one tile = (width mm ÷ 1000) × (height mm ÷ 1000) in square meters (m²). For example, a 300×300 tile is 0.3 × 0.3 = 0.09 m². The number of tiles is the installation area divided by this value, plus waste, rounded up.

Should I account for grout joint spacing?

Adding the grout joint spacing (usually 2-5 mm) slightly increases the effective area each tile occupies, which slightly reduces the number of tiles needed. Since this often cancels out with the waste allowance, this calculator uses the actual tile dimensions excluding grout and corrects with the waste rate.

How many tiles are usually in a box?

Tiles per box depend on the tile size. A 300×300 box often holds 11 tiles, and a 600×600 box often holds 4. Enter the tiles per box in this calculator to also get the number of boxes; buy by rounding up to full boxes.

Is this tile count accurate?

This calculator gives a reference estimate based on actual tile dimensions and a waste rate. Real quantities vary with the layout pattern, wall and floor shape, and installer skill, so buy with extra and confirm the final quantity with your contractor.

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Last updated: 2026-06-25