How to calculate how many tiles you need
- Measure the area: length × width (or height for walls).
- Work out the area of one tile including the grout gap.
- Divide the area by the tile area, then add a waste allowance for cuts and breakage.
- Round up to whole boxes.
For L-shaped rooms, split the floor into rectangles, calculate each one, and add them up.
How much extra tile should I buy?
10% extra is the standard for a straight layout. Diagonal and herringbone patterns produce more offcuts, so use 15%. Large-format tiles in a small room with many corners can need 20% or more.
How many 12×12 tiles in a 10×8 room?
80 ft² ÷ about 1.02 ft² per tile (with a ⅛″ grout gap) ≈ 79 tiles. With 10% waste you need around 87 tiles.