About This Calculator
This calculator estimates the number of floor tiles needed for a room, accounting for tile size, grout lines, pattern type, and wastage.
Common Tile Sizes
| Size | Tiles per m² | Best For |
|---|---|---|
| 200 × 200mm | 25 | Small bathrooms |
| 300 × 300mm | ~11 | Kitchens, bathrooms |
| 400 × 400mm | ~6 | Living areas |
| 600 × 600mm | ~3 | Large rooms, modern look |
| 300 × 600mm | ~5.5 | Rectangular pattern |
Laying Patterns
- Straight: Standard grid pattern. Least wastage (~5-10%)
- Diagonal: Tiles at 45° angle. More cuts, ~15% extra wastage
- Herringbone: Interlocking pattern. Most wastage (~20%)
Ordering Tips
- • Add 10% for straight patterns, 15% for diagonal, 20% for herringbone
- • Buy all tiles from the same batch to ensure colour match
- • Keep spare tiles for future repairs
- • Check box quantity - usually 5-12 tiles per box
- • Measure carefully - account for fixed fittings (cabinets, etc.)
Grout Lines
Standard grout lines are 2-3mm. Larger tiles may need wider gaps (3-5mm) to accommodate slight size variations. Include grout width in your calculations.
Ready to Calculate?
Enter your room dimensions, tile size, and pattern to get an estimate.
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NAIBC / IRC codes
References & Sources
Standards Cited
- ANSI A108/A118/A136 — ANSI Standards for Installation of Ceramic Tile
Defines standard tile installation methods, including layout, spacing, and wastage considerations for North American construction - TCNA Handbook — Tile Council of North America — Handbook for Ceramic, Glass, and Stone Tile Installation
Industry-standard reference for tile sizing, coverage rates, and installation best practices in North America
Formulas Used
- Effective Tile Area:
tileArea = ((tileLength + gap) / 1000) x ((tileWidth + gap) / 1000)
Source: ANSI A108 / TCNA Handbook — Grout gap is added to each tile dimension to account for joint width - Tiles per m²:
tilesPerM2 = 1 / effectiveTileArea
Source: Industry standard calculation - Total Tiles with Pattern and Wastage:
total = ceil(baseTiles x max(wastageMultiplier, patternMultiplier))
Source: Industry standard practice — The higher of user wastage or pattern wastage is applied (not both). Pattern multipliers: straight 1.0, diagonal 1.15, herringbone 1.20
Key Assumptions
- Diagonal tile laying adds 15% extra wastage for angled cuts — TCNA Handbook / manufacturer guidance
- Herringbone pattern adds 20% extra wastage for complex cuts — TCNA Handbook / manufacturer guidance
- Standard box contains 6 tiles (user should verify with actual product) — Common US manufacturer packaging
- Default 10% wastage for cuts and breakages on straight lay — TCNA Handbook recommended practice
- Common US tile sizes include 12"x12", 12"x24", 6"x24" (plank), and 18"x18" — TCNA Handbook / manufacturer standard sizes