Tile Calculator

How many tiles you need for a floor or wall: tile size, grout joint and extra for cuts, with boxes and cost, in inches or millimetres.

The number of tiles depends on the tile size and the grout joint around each one: each 12 × 12 in tile with a 1/8 in joint takes up 12.125 × 12.125 in, so a square foot takes slightly fewer than one tile. A 10 × 8 ft floor is 80 ft², which is about 78 tiles, or 87 once you add 10% for cuts and breakage. In metric, a 3 × 2.5 m floor of 300 × 300 mm tiles with 3 mm joints takes 82 tiles, or 90 with 10% extra. Enter the areas, choose a tile size or type your own, set the joint and the extra, and the calculator gives the tiles, boxes and cost.

Units
Area
ft
ft
Feet and inches work too: type 12'6 or 12.5.
in
%
Tiles
87

incl. 10% extra

Boxes
–

enter tiles per box

Area
80 ft²

88 ft² with extra

Tiles per ft²
0.98

with joints

How it was worked out
  1. Area: 10 ft × 8 ft = 80 ft²
  2. Each 12 × 12 in tile plus a 0.13 in joint covers 12.13 × 12.13 in: 0.98 tiles per ft²
  3. 80 ft² × 0.98 = 78.36 tiles; plus 10% = 86.19, rounded up to 87 tiles

Allow about 10% extra for straight layouts and 15% or more for diagonal or herringbone patterns, small rooms with lots of cuts, and large-format tiles. Keep a few spare tiles from the same batch for repairs.

Common use cases

  • Order floor tiles for a bathroom, kitchen or hallway
  • Wall tiles for a shower, splashback or feature wall
  • Compare how many large-format and small tiles a room needs
  • Work out boxes and cost before visiting the tile shop

How to use

  1. Choose inches or millimetres.
  2. Enter the floor or wall area. Add more areas for an L-shaped room or several walls.
  3. Choose the tile size and grout joint, and the extra for cuts: more for diagonal or herringbone layouts.
  4. Enter the tiles per box and a price to see boxes and cost.

FAQ

How many tiles do I need per square foot or square metre?

Divide the area by the space one tile takes up including its joint. Without joints, 12 × 12 in tiles are 1 per ft² and 300 × 300 mm tiles are 11.1 per m²; with a 3 mm joint, 300 mm tiles come to about 10.9 per m².

How much extra tile should I buy?

About 10% for a straight layout in a simple room, and 15% or more for diagonal and herringbone patterns, rooms with lots of cuts and large-format tiles. Keep a few spares from the same batch for future repairs.

What size grout joint should I use?

Follow the tile maker's guidance. Rectified tiles are often laid with narrow joints of around 1/16 to 1/8 in (2 to 3 mm), while handmade and rustic tiles need wider joints. The grout calculator works out how much grout your joints need.

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