Bathroom Tile Calculator (Tiles, Boxes, Adhesive & Grout)
Use this free calculator to estimate how many tiles, boxes, adhesive bags and grout you need for bathroom floors or walls. Enter your area (or room dimensions), tile size, waste allowance and packaging details. Works in metric (m, mm, m²) and imperial (ft, in, ft²).
How to use
- Choose units (Metric or Imperial) and tiling type (Floor or Wall).
- Either enter room dimensions (length × width or wall length × height × count) or a total tiled area.
- Enter tile size (length × width), waste %, and your packaging: tiles per box or box coverage.
- Optionally enter adhesive coverage (m²/bag or ft²/bag) and grout coverage (m²/kg or ft²/kg) from your product label.
- Click Calculate to see tiles, boxes, adhesive and grout estimates.
Worked example
Floor, metric: Room 2.4 m × 1.8 m = 4.32 m², Tile 300 × 300 mm, Waste 10%, Tiles/box 11, Adhesive coverage 5 m²/bag, Grout coverage 3 m²/kg.
- Tiled area with waste: 4.32 × 1.10 = 4.75 m²
- Tile area: 0.3 × 0.3 = 0.09 m² → Tiles needed: 4.75 ÷ 0.09 ≈ 53 tiles (rounded up)
- Boxes: 53 ÷ 11 ≈ 4.82 → 5 boxes
- Adhesive: 4.75 ÷ 5 ≈ 1 bag; Grout: 4.75 ÷ 3 ≈ 1.6 kg (≈ 2 kg)
Bathroom tile calculator
FAQs
How much waste should I allow?
7–12% is common. Use the higher end for diagonal patterns, small rooms with many cuts, or patterned/veined tiles that require layout matching.
Should I enter tiles per box or box coverage?
Either works. If your box lists tiles per box, use that. If it lists coverage (m² or ft²), use box coverage instead.
How do I account for niches, windows and doors?
Use the Subtract openings field to remove their area from the total tiled area.
How many adhesive bags or grout do I need?
Coverage varies by product, trowel size and joint width. Enter the coverage printed on your adhesive/grout packaging for best accuracy.