Calculation
Surface area is divided by one tile's area. Waste is applied before the result is rounded to whole tiles and then whole boxes.
Tile / material estimate
Tile calculator
Turn room and tile dimensions into a box-ready purchase quantity, with editable waste, pack size, and material price.
From measured area to whole boxes.
Waste
The 10% default is a common planning allowance referenced by Home Depot. Diagonal or intricate layouts may need more. Source
Before you order
Let the layout set the allowance.
Measure the tiled surface only
Split irregular rooms into rectangles, calculate each area, then add the dimensions before entering them here.
Increase waste for complex cuts
Ten percent suits many straight layouts; diagonals, niches, fragile tile, and matching patterns can require more.
Verify the carton
Use the actual pieces per box and keep spare tile from the same lot for future repairs.