Floor Tile Calculator — Tiles, Adhesive & Grout for Any Room

Our floor tile calculator divides your floor area by the area of each tile to determine the number of tiles needed. We then add wastage based on your laying pattern and calculate adhesive and grout quantities using UK product coverage rates.

For an L-shaped room, press Add section and enter each rectangle as its own section. Tile counts are rounded up per section and then added together, covering the extra cut tiles at the junction between sections, while adhesive and grout use the combined area because they are spread continuously. Use three sections for a T or U shape.

The formula

Tiles needed = (Floor area ÷ Tile area) × (1 + Wastage %)

For example, a 20 m² room with 300×300mm tiles in a straight pattern: 20 ÷ 0.09 = 222.2, rounded up to 223 tiles, + 10% wastage = 245.3, rounded up to 246 tiles.

Wastage by pattern

• Straight/grid: 10% — minimal cuts at edges
• Diagonal/diamond: 15% — more cuts at all walls
• Herringbone: 20% — many angled cuts required

Adhesive and grout

• Adhesive: a 25kg bag covers ~4.5 m² for standard tiles with a 6–10mm notched trowel, dropping to ~3 m² for large-format tiles (600mm+) where a 12mm notch plus back-buttering is needed for full bed coverage. The calculator sets this automatically and you can override it in Advanced Options.
• Grout: varies by tile size — smaller tiles need more grout per m² due to more joint lines. Our estimate assumes a 3mm joint at ~12mm depth (conservative); check your grout datasheet for the exact tile thickness.