Tile Calculator
Calculate tiles needed for floors, walls, or splashbacks in your NZ home. Includes wastage allowance and grout coverage.
About this calculator
This calculator implements tile coverage and wastage guidelines from Tile Council NZ + BRANZ. Last consulted 15 November 2025. Verify the figures yourself by following the link.
NZ tile costs
Indicative 2026- •Common sizes: 300×300, 450×450, 600×600, 600×1200 mm
- •Budget porcelain: $25-50/m²
- •Mid-range: $50-100/m²
- •Premium (natural stone): $100-300/m²
- •Waste allowance: 10% straight / 15% diagonal pattern
- •Tile install + adhesive: $50-100/m²
Disclaimer
This calculator provides estimates for general information purposes only. Results are based on standard formulas and may not reflect your individual circumstances. Always consult a qualified professional for advice specific to your situation.
How tile quantity is calculated
Total tiles = (area ÷ tile area) × 1.10 (10% waste). Round up. Larger tiles = less waste but harder to cut around fixtures.
- 1
Tile area
Tile_area_m² = tile_width × tile_height (in m)
300×300mm = 0.09 m². 600×600mm = 0.36 m².
- 2
Tiles needed
Tiles = ⌈(room_area_m² ÷ tile_area_m²) × 1.10⌉
Round up to nearest whole tile + 10% waste.
- 3
Plus extras for repairs
Buy 5-10 extra (same batch number) for future repair
Batch numbers can vary in colour — buy extras from same lot.
Worked example
Inputs: 10m² bathroom, 600×600mm tiles ($60 each)
Result: Tiles: (10 ÷ 0.36) × 1.10 = 31 tiles × $60 = $1,860.
Frequently Asked Questions
How many tiles do I need for a bathroom?
How much wastage should I allow for tiles?
How much does tile installation cost in NZ?
Do NZ tile prices include GST?
A tile calculator works out the number of tiles you need for a floor, wall, or splashback project. It accounts for the area being tiled, the size of each tile, plus a wastage allowance (usually 10%) for cuts and breakages.
How this calculator works
Enter the room dimensions (length × width) or the total area, the tile size (e.g. 300×300mm, 600×600mm), and your wastage percentage. The calculator divides the total area by the tile area, adds wastage, and rounds up. Two practical rules save most re-orders: tiles are sold by the box (typically 1-1.5 m² per box), so round up to whole boxes and keep a spare box for future repairs — matching a discontinued tile years later is nearly impossible. And check the batch (shade) code on every box before laying: colour varies slightly between production runs. Diagonal and herringbone layouts generate more offcuts, which is why their wastage allowance rises to 15%.
Common NZ Tile Sizes & Coverage
| 300×300mm (small) | ~11 tiles per m² |
| 450×450mm (medium) | ~5 tiles per m² |
| 600×600mm (standard) | ~3 tiles per m² |
| 600×1200mm (large format) | ~1.4 tiles per m² |
| Recommended wastage | 10% (15% for diagonals/herringbone) |
Worked Examples
Bathroom floor 3m × 2.5m, using 600×600mm tiles
~22 tiles needed (incl 10% wastage)
- Area: 3 × 2.5 = 7.5 m²
- Tile area: 0.6 × 0.6 = 0.36 m²
- Tiles needed: 7.5 / 0.36 = 20.8
- Add 10% wastage: 22.9 → round up to 23 tiles
Kitchen splashback 4m × 0.6m, using 300×300mm tiles
~30 tiles needed (incl 10% wastage)
- Area: 4 × 0.6 = 2.4 m²
- Tile area: 0.3 × 0.3 = 0.09 m²
- Tiles needed: 2.4 / 0.09 = 26.7
- Add 10% wastage: 29.3 → round up to 30 tiles
Built and maintained by Konstantin Iakovlev. Data sourced from the IRD and official New Zealand government sources.
Last reviewed: