Calculadora de Telhado Online Grátis
Roofing area, shingles and material cost with pitch and waste factor
The Roofing Calculator computes the true sloped surface area of a roof from the ground footprint and pitch angle, then estimates the number of shingles or roofing sheets needed including a waste allowance for cutting and overlapping. Roofers, building contractors, and homeowners getting replacement quotes use it to cross-check material estimates before purchasing.
Frequently Asked Questions
Sobre Esta Calculadora
Roofing materials are ordered by the square (100 square feet or ~9.3 m²), but the sloped surface area is always larger than the footprint you measure on a floor plan. A 4:12 pitch adds about 5.4% to the area; a steep 12:12 pitch (45°) adds over 41%. Applying the pitch multiplier before calculating shingle quantities is essential — it's the single most common mistake in DIY roofing material estimates.
This calculator applies the correct pitch multiplier for both gable and hip roofs, then adds a configurable waste factor (typically 10% for straight cuts, 15–20% for complex roofs with many valleys and dormers). It outputs results in both m² and roofing squares to match different supplier ordering systems.
Roofing costs also include underlayment, ridge caps, flashing, and fasteners — materials not captured here but which typically add 15–25% to the shingle cost. Use the Construction Cost Calculator to build a complete budget estimate once you have the material quantities from this tool.
A Calculadora de Telhado calcula a verdadeira área de superfície inclinada de um telhado a partir da área do solo e do ângulo de inclinação.
Exemplo Resolvido
Calculating shingles for a 10 m × 8 m house with a 4:12 pitch
Entradas:
- Roof footprint: 10 m × 8 m (single gable)
- Pitch: 4:12 (4 inches rise per 12 inches run)
- Waste factor: 10%
Passo a Passo:
- Pitch multiplier for 4:12: √(1 + (4/12)²) = √(1 + 0.111) = √1.111 = 1.054
- Sloped roof area: 10 × 8 × 1.054 = 84.3 m² (both sides of gable)
- Add 10% waste: 84.3 × 1.10 = 92.7 m²
- One roofing square = 9.29 m² (100 sq ft)
- Squares needed: 92.7 ÷ 9.29 = 9.98 → 10 squares
- Standard bundle covers ~3.3 m²; bundles needed: 92.7 ÷ 3.3 = 28.1 → 29 bundles