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Matholio

Tile calculator

Find how many tiles and boxes of tile to buy for a floor. Enter the room size, the tile size and the coverage printed on the box.

Updated Checked by Matholio Editorial TeamFree, no sign-up
LengthWidth

How to measure

Measure the floor wall to wall, then check the tile size and box coverage on the label.

Floor size
Tile

Printed on the box label.

Tiles needed

88 tiles

Buy 9 boxes of tile

Floor area80 sq ft
One tile covers1 sq ft
Area with 10% waste88 sq ft
Coverage per box10 sq ft

Grout joints are ignored, which adds a small safety margin. Tiles and boxes are rounded up.

How many tiles do I need?

Divide the floor area by the area of one tile, then add 10% for cuts and breakage, or 15% or more for diagonal layouts. A 10 × 8 ft floor is 80 sq ft; with 12 × 12 in tiles and 10% waste you need 88 tiles, or 9 boxes that cover 10 sq ft each.

Worked example: a 10 × 8 ft bathroom floor

  1. Floor area: 10 × 8 = 80 sq ft.
  2. One 12 × 12 in tile covers 144 ÷ 144 = 1 sq ft.
  3. Tiles with 10% waste: 80 ÷ 1 × 1.10 = 88 tiles.
  4. Boxes: 88 ÷ 10 = 8.8, rounded up to 9 boxes.

Tiles needed for 100 square feet

A 10 × 10 ft floor with 10% waste. Larger tiles mean fewer pieces, but each bad cut wastes more area.

Tiles needed for 100 sq ft by tile size
Tile size One tile covers Tiles needed
6 × 6 in 0.25 sq ft 440
12 × 12 in 1.00 sq ft 110
12 × 24 in 2.00 sq ft 55
18 × 18 in 2.25 sq ft 49
24 × 24 in 4.00 sq ft 28

How the calculator works

Tile area (sq ft) = tile length (in) × tile width (in) ÷ 144

Tiles = floor area ÷ tile area × (1 + waste %), rounded up

Boxes = floor area × (1 + waste %) ÷ coverage per box, rounded up

Grout joints are left out, which slightly overstates the tile count and adds a small safety margin. Flooring Clarity suggests 5% to 7% extra for a simple straight layout, 10% to 20% for complex patterns or small tiles, and 15% to 25% for diagonal layouts.

Frequently asked questions

How many tiles do I need for 100 square feet?

With 12 × 12 in tiles and 10% waste, 110 tiles. With 12 × 24 in tiles, 55 tiles, and with 24 × 24 in tiles, 28 tiles.

How much extra tile should I buy?

About 10% for a straight layout and 15% or more for a diagonal layout. Keep a few spare tiles from the same lot for future repairs.

Do I need to account for grout lines?

Not for an estimate. Leaving grout out makes the count a little higher than the exact number, which adds a small margin.

Can I use this for wall tile?

Yes. Enter the wall width and height instead of the floor length and width, and subtract large openings such as windows yourself.

Sources

  1. Flooring Clarity, How Much Extra Tile to Buy for a Project