How this is calculated
Room area divided by the area of one tile gives a raw tile count. Diagonal layouts, niches, and breakage mean you almost never order that exact number — the waste field adds the buffer trades use.
Boxes are rounded up because stores do not sell half a box. If your tile comes in a different pack size, change the tiles-per-box field in the cost section.
Formula & methodology
Tiles = ceil((Room area ÷ Tile area) × (1 + waste %)). Boxes = ceil(Tiles ÷ tiles per box).
Worked example
A 10 ft × 8 ft bathroom, 12 in × 12 in tiles, 10% waste
- 1.Room area = 80 ft²
- 2.Tile area = 1 ft × 1 ft = 1 ft²
- 3.Raw count = 80 tiles; with 10% waste = 88 tiles
- 4.At 10 tiles per box → 9 boxes
Frequently asked questions
How much tile waste should I add?
10% covers a straightforward rectangular room with a straight lay. Diagonal patterns, large format tile, or many cuts often need 12–15%.
Does this include wall tile?
It is set up for floor area. For walls, measure wall area separately or use room perimeter × height minus openings.
Large format tiles?
Enter the actual tile dimensions. Large tiles have fewer grout lines but break more easily — consider 12–15% waste.
Are adhesive and grout included?
No. This is tile count and box quantity only. Adhesive coverage depends on trowel size and substrate.
What if my room is not rectangular?
Split the floor into rectangles, run the calculator for each, and add the tile counts. Irregular rooms need more waste.
UK and US sizes?
Use the unit toggle. Enter tile size in inches or centimetres as printed on the box.
Last updated 2026-09-01. Formulas are planning methods — confirm with a supplier before you order.