Construction estimator
Tile Calculator
Enter the size of the floor or wall, leave out doors or fixed areas, and pick the tile size to see how many tiles to buy. Add the tiles in a box to see the boxes too. Your entered values stay out of analytics.
Formula and assumptions
Area = length × width − area to leave out. Area per tile = tile length × tile width. Tiles = area × (1 + wastage) ÷ area per tile, rounded up. Boxes = tiles ÷ tiles per box, rounded up.
- Tiles are counted by face area: the area divided by the area of one tile. Grout joints are not added to the count, because the joint width follows the tile manufacturer's installation specification. Tile sizes are the nominal sizes as sold.
- Wastage covers cuts and breakage and is added to the area before dividing by the tile area. It is 10% by default. Diagonal or patterned layouts and many cuts may need more.
- Boxes are worked out only if you enter the number of tiles per box.
- An estimate for buying tiles. It does not cover grout, adhesive, skirting, layout patterns, borders or waterproofing.
- Areas are shown to 2 decimal places. Tiles and boxes to buy are rounded up to whole numbers.
Formula version 1.0, last reviewed Reviewed by an external trade reviewer, 6 October 2026; released by the owner.
Frequently asked questions
How much wastage should I add?
The tool starts at 10% for cuts and breakage. Many people add more for diagonal or patterned layouts. Change it to suit your job.
Which tile size do I enter?
The size printed on the box, in millimetres. If your tile is not in the list, choose Custom size and enter its length and width.
Does the grout joint change the count?
No. The count uses the face area of each tile. A layout with many cuts, or a diagonal or patterned layout, may need a higher wastage allowance.
How are boxes worked out?
Enter how many tiles are in one box. The boxes are the tiles needed divided by that number, rounded up, so you may end up with a few spare tiles.
What does this not include?
Grout, adhesive, skirting, borders, layout patterns, tile thickness and waterproofing. It estimates the number of tiles only.