How to Calculate How Many Tiles You Need

Calculating tiles for a floor or wall is straightforward once you know the room area and tile size. The key is accounting for grout joints and a waste factor for cutting.

The Formula

Tiles = (Room Area ÷ Tile Area) × (1 + Waste %)
Tile area includes the grout gap on each side.

Example

For a 4 m × 5 m = 20 m² room with 60×60 cm tiles and 3 mm grout:

  • Tile area with grout = 0.603 × 0.603 = 0.3636 m²
  • Raw tiles = 20 ÷ 0.3636 = 55 tiles
  • With 10% waste = 61 tiles (7 boxes of 10)

When to Increase Waste Factor

  • 10% — simple rectangular rooms, straight layout
  • 15% — diagonal tile layout, L-shaped rooms
  • 20%+ — complex patterns (herringbone, chevron), many cuts

Converting tile area from m² to ft²?

Open m² to ft² Converter →