Work out how many tiles to buy for a floor, backsplash or shower wall. Enter the area and the tile size, choose a waste allowance for cuts, and get the number of tiles and boxes.
Last updated: October 2, 2026
From the box label.
Area–
Tiles needed–
Boxes–
For L-shaped rooms, split the space into rectangles and add the results. Keep a few spare tiles for future repairs.
How the calculation works
tile area (sq ft) = tile length (in) × tile width (in) ÷ 144
tiles = area ÷ tile area × (1 + waste %), rounded upHow much extra to buy
- About 10% for a standard straight layout in a simple room.
- About 15% for diagonal, herringbone or other patterns with many angled cuts.
- More for rooms with many corners, large tiles or natural stone with variation.
Buying all tiles at once from the same production lot keeps color consistent. Leftovers are useful if a tile ever cracks.
Frequently asked questions
Do grout lines change the count?
Slightly: grout joints mean each tile covers a bit more area, so you need marginally fewer tiles. The waste allowance more than covers this, so the calculator ignores it.
Should I subtract the area under cabinets?
Yes, for floors where cabinets or a tub will sit permanently and won’t be tiled underneath. Measure only the area you’ll actually tile.