Tile Calculator: How Many Tiles Do I Need

It depends entirely on tile size, which the tool derives from your dimensions. A 12 by 12 inch tile is exactly one per square foot, a 6 by 6 inch tile is four, and an 18 by 18 inch tile is about 0.44 because each tile covers more than a square foot.

The area is multiplied by 1 plus the waste percent before dividing by tile size. A 10 percent allowance over 100 square feet means the tool sizes for 110 square feet of tile, so trimmed and broken pieces do not leave you short.

Around 10 percent suits a straight grid on a square room. Step up to 15 percent or more for diagonal, herringbone or offset patterns, or for rooms with many corners and cutouts, because cut offs from those layouts often cannot be reused.

You cannot buy a fraction of a tile or a partial box, so both round up to the next whole unit. The leftover doubles as spares for breakage during setup and for future repairs where the exact color may no longer be sold.

Yes. Enter the wall's length and height in place of the floor length and width. The calculation is the same because it depends only on total surface area and the size of one tile.

No. It is optional. Leave it at zero or blank and the box count simply shows a dash while the tile count still works. Fill it in from the product listing when you want an exact number of boxes to order.

For typical joints you do not need to. Grout lines are thin and the waste allowance already absorbs them. If you are using very wide joints, nudge the waste percent up a point or two to stay on the safe side.

Not in a single run, because the math assumes one uniform tile. Estimate each tile size against the area it will cover separately, then add the results together.

Yes. The tool runs entirely in your browser, so the dimensions you enter are never sent to a server and the page keeps working without a connection.