Roof Tile Calculator

How to Use This Calculator

This roof tile calculator helps you estimate the number of tiles, battens, and screws required for your roofing project. Start by measuring the roof area in square meters. If you have a pitched roof, measure the horizontal projection and then adjust for slope, or directly measure the sloped surface. Next, enter the roof slope in degrees. The slope is critical because it determines the actual surface area—steeper roofs have more area than their footprint. Finally, select the tile type: Romana, Portuguesa, or Sanduíche. Each type has different dimensions and coverage rates.

Formula and Methodology

The calculator uses the following logic: First, it converts the roof area to the actual sloped area using the formula: Sloped Area = Area / cos(Slope). This accounts for the increase in surface area due to the pitch. Then, it multiplies the sloped area by the number of tiles per square meter for the selected tile type. A waste factor of 5% is added to account for cuts and breakage. The result is rounded up to the nearest whole tile. For battens, the calculator divides the sloped area (converted to square centimeters) by the product of batten spacing (in cm) and 100 cm (standard batten length). This gives the total linear meters of battens needed, which is then converted to the number of battens (assuming standard lengths). Screws are calculated as 3 per tile, a common practice for secure fixation.

Practical Examples

Suppose you have a roof area of 100 m² with a slope of 30 degrees. You choose Portuguesa tiles. The sloped area is 100 / cos(30°) ≈ 115.47 m². Portuguesa tiles require 17 tiles per m², so total tiles = 115.47 × 17 × 1.05 ≈ 2060 tiles. Batten spacing is 32 cm, so battens = (115.47 × 10000) / (32 × 100) ≈ 361 battens. Screws = 2060 × 3 = 6180 screws. If you used Romana tiles instead, tiles per m² is 16, so tiles = 115.47 × 16 × 1.05 ≈ 1940 tiles, and batten spacing is 34 cm, giving fewer battens.

Tips and Best Practices

Always consult local building codes and manufacturer instructions for specific requirements. Consider adding extra tiles for future repairs. For roofs with complex shapes, valleys, or hips, increase waste factor to 10-15%. Ensure battens are properly treated and spaced according to tile type. Use corrosion-resistant screws, especially in coastal areas. If you're unsure about slope measurement, use a digital level or consult a professional. This calculator provides a good estimate but should be verified by a roofing specialist for critical projects.