Roof Tile Estimator
Enter your roof measurements in meters. This calculator estimates tile count, packs, and cost.
How this roof tile calculator works
A roof tile estimate starts with area. This tool uses your roof's projected footprint (length × width) and adjusts it for pitch so the real sloped surface area is more accurate. Once that area is known, it multiplies by your tile coverage rate and then adds waste allowance.
Formula used:
Sloped Roof Area = (Length × Width) ÷ cos(Pitch)
Total Tiles = Sloped Roof Area × Tiles per m² × (1 + Waste %)
What to measure before ordering tiles
1) Roof length and width
Measure the roof footprint from plan view (horizontal). If your roof has multiple sections, calculate each section separately and add the totals.
2) Roof pitch
Pitch has a major impact on surface area. A steeper roof needs more tiles than a low-pitch roof with the same footprint dimensions.
3) Tile coverage rate
This depends on tile profile, overlap, batten spacing, and manufacturer specs. Always use the product data sheet if available.
Typical coverage ranges (guide only)
- Concrete interlocking tiles: approximately 9 to 11 tiles per m²
- Clay pantiles: approximately 12 to 16 tiles per m²
- Large-format flat tiles: approximately 9 to 12 tiles per m²
- Small plain tiles: often 50+ tiles per m²
These values vary by brand and installation method. Your exact tile count should be based on technical specifications for your selected tile.
Recommended waste allowance
Most projects include extra material for cuts, breakage, and future replacements. Common allowances:
- Simple roof layouts: 5% to 10%
- Complex roofs with hips/valleys/dormers: 10% to 15%+
- Small repairs: often higher percentage due to offcuts
Example estimate
If your roof is 12 m long and 8 m wide, with a 30° pitch, and your chosen tile uses 10 tiles per m²:
- Projected area = 12 × 8 = 96 m²
- Pitch factor = 1 / cos(30°) ≈ 1.1547
- Sloped area = 96 × 1.1547 ≈ 110.85 m²
- Base tiles = 110.85 × 10 ≈ 1,108.5 tiles
- With 10% waste = about 1,220 tiles (rounded up)
Common estimating mistakes to avoid
- Using floor area instead of roof area
- Ignoring pitch correction
- Not including waste allowance
- Forgetting ridge, hip, valley, and verge accessory pieces
- Not checking local code requirements and manufacturer instructions
Final tip
This calculator gives a strong planning estimate for materials and budget. Before final purchase, confirm counts with your roofer, supplier, or manufacturer takeoff service. That final check can save both money and delays on install day.