Flooring Calculator
Flooring Calculator
Estimate tiles or planks for a rectangular floor area. Enter room dimensions, optional non-floor areas, and your flooring piece size with grout joint. The calculator gives you order area plus piece count with waste — and optional box quantities.
Flooring Calculator
Estimate tiles/planks for a rectangular floor area (minus openings) with waste allowance
Results
Enter dimensions above to calculate
Tile Module vs Tile Size
The tile "module" includes the grout joint on each edge. The calculator uses module area for accurate piece counts that match a real laid floor.
Step-by-Step Formulas
1. Gross Floor Area
Measure to the longest wall-to-wall dimension in each direction. For L-shaped or irregular rooms, break the space into rectangles, calculate each, and sum the areas.
2. Subtract Non-Floor Areas
Subtract fixed islands, hearths, or built-in furniture bases that won't receive flooring. If uncertain, leave as 0 and use a slightly higher waste allowance.
3. Add Waste Allowance
Waste covers offcuts, breakage, and layout. 5–10% suits straight installs. Budget 10–15% for diagonal runs or herringbone patterns where offcut rates are higher.
4. Convert Area to Pieces
Tile counts use the "module" area (tile + grout joint). Plank counts use the plank face area (no joint for click-lock products). Results round up to whole pieces.
Waste Allowance by Pattern Type
| Layout pattern | Recommended waste |
|---|---|
| Straight run (grid or brick bond) | 5–8% |
| Straight run (many cuts / irregular room) | 8–12% |
| Diagonal (45°) tile or plank | 12–15% |
| Herringbone or chevron | 15–20% |
| Complex pattern (multiple sizes) | 18–25% |
Typical Grout Joint Width by Tile Size
| Tile size | Typical grout joint |
|---|---|
| Mosaic (≤50 mm) | 1–3 mm |
| Small (50–150 mm) | 2–3 mm |
| Medium (150–300 mm) | 3–5 mm |
| Large (300–600 mm) | 3–6 mm |
| Extra-large (600 mm+) | 5–10 mm |
* Always follow tile manufacturer and tile-setter guidelines for joint width — rectified tiles can take narrower joints than pressed/non-rectified tiles.
Worked Example
A 5 m × 4 m room, no non-floor areas, 10% waste. 600 × 600 mm tile with 3 mm grout joint.
💡 Pro tip
Order tiles from a single batch (shade lot number). Even tiles with identical colour codes can vary slightly between production runs. Keep 5–10% of tiles in reserve for future repairs — matching discontinued tiles years later is often impossible.
Frequently Asked Questions
- What waste percentage should I use for flooring?
- For simple rooms and straight installs, 5–10% is common. For diagonal or herringbone patterns, 10–15% is safer.
- Should I subtract kitchen cabinets or fixed islands?
- If flooring will not be installed under fixed items, you can subtract those areas. If uncertain, leave as 0 and use a slightly higher waste allowance.
- Why does tile count include grout joint thickness?
- Using tile module size (tile + grout joint) matches real layouts more closely since every tile has a joint on each edge in the finished installation.
- Do plank counts include an expansion gap?
- No — the expansion gap is covered by skirting/base board and does not require extra planks. The calculator estimates plank face area only.