Tile Calculator

A tile calculator turns your room size and tile size into the number of tiles to buy — with a waste allowance so cuts, breakages and the odd dud tile do not send you back to the store mid-job. Measure by room dimensions or total area, set your tile size, and it does the rest.

Your measurements

Result

It also builds a quick shopping list: the tiles, the thinset to stick them down and the spacers to keep the grout lines even. Tile is a low-competition, ships-to-door category, which makes it an easy early win.

How it is calculated

Tiles needed = floor area ÷ tile area, multiplied by one plus the waste percentage, then rounded up. Working in a common unit avoids inch-versus-foot mistakes. Diagonal and patterned layouts waste more, which is why the allowance is adjustable.

Steps

Choose whether to enter room length × width, or a total area.
Enter the measurements in feet (or metres).
Enter your tile size — 12 × 12 inches is a common floor tile.
Set a waste allowance: 10% for a simple layout, 15% for diagonal or patterned.
Read the tile count and order from one batch for a consistent colour.

Worked example

A 12 ft × 10 ft floor is 120 sq ft. With 12-inch tiles (1 sq ft each) and 10% waste, you would buy 132 tiles.

Common questions

How much extra tile should I buy?

Ten percent for a straight layout, 15% for diagonal or patterned, and more for lots of small cuts around fixtures. Keep a few spares afterwards.

How do I measure for tile?

Measure the length and width of the area and multiply for the square footage. For odd shapes, split the room into rectangles and add them up.

How many tiles in a box?

It varies by tile size — the box states its coverage in square feet. Divide your area by the box coverage to get the number of boxes.

Do I need more for wall tile?

The maths is the same; just measure the wall area instead of the floor. Add extra around windows and for any border or feature rows.