Calculadora de Tejados Gratis
Estima cuadrados de tejado, paquetes de tejas y superficie real a partir de la planta y la pendiente. Gratis, rápido y funciona por completo en tu navegador sin necesidad de registro.
Actualizado
Roofing material
Extra material for cuts, spillage and breakage.
Roofing needed
14.76
squares
- Actual roof area
- 1,476ft²
- Building footprint
- 1,200ft²
- Shingle bundles3 bundles per square
- 45bundles
- Pitch multiplier applied
- 1.1180×
How this is calculated
roof area = footprint × √(1 + (rise ÷ 12)²); squares = area ÷ 100; bundles = squares × 3
- The pitch multiplier is the true slope factor: a 6/12 roof is 1.118× its footprint, a 12/12 roof 1.414×.
- One "square" is 100 ft² of roof; standard 3-tab shingles come 3 bundles to the square.
- Footprint is treated as a simple rectangle — add each section separately for an L-shaped or complex roof.
- Hips, valleys and ridge cap are not itemised; the waste allowance is where they are absorbed.
Preguntas Frecuentes
How does the Roofing Calculator work?
It applies the formula roof area = footprint × √(1 + (rise ÷ 12)²); squares = area ÷ 100; bundles = squares × 3. Enter your measurements and the result updates instantly in your browser — nothing is uploaded and no sign-up is needed.
Why should I include a waste allowance?
Offcuts, spillage, breakage and an uneven sub-base all consume material that the raw geometry does not account for. The default allowance is deliberately modest; increase it for complex layouts, and remember that running short usually costs more in a second delivery than the surplus did.
Are the results exact?
They are a close estimate, not a guarantee. The pitch multiplier is the true slope factor: a 6/12 roof is 1.118× its footprint, a 12/12 roof 1.414×. Real materials vary by supplier, moisture content and compaction, so confirm the rate with your supplier before placing a large order.
Is this tool free?
Yes, completely free with no registration. All calculations happen client-side in your browser.
Does it work on mobile?
Yes. The calculator is fully responsive and works on phones and tablets in any modern browser — useful when you are measuring on site.
Herramientas Relacionadas
Calculadora de Asfalto Gratis
Calcula el tonelaje de asfalto para un camino de entrada o una parcela a partir del área y el espesor compactado. Gratis, rápido y funciona por completo en tu navegador sin necesidad de registro.
Calculadora de Placas de Yeso Gratis
Estima placas de yeso, tornillos y pasta de juntas para una habitación a partir de su perímetro y la altura de pared. Gratis, rápido y funciona por completo en tu navegador sin necesidad de registro.
Calculadora de edad gratis en línea
Calcula tu edad exacta en años, meses y días con signos del zodiaco. Gratis, rápido y funciona completamente en tu navegador sin necesidad de registro.
Calculadora de porcentajes gratis
Calcula porcentajes fácilmente con varios modos de cálculo. Gratis, rápido y funciona completamente en tu navegador sin necesidad de registro.
About the Roofing Calculator
The Roofing Calculator converts a building footprint and roof pitch into the true sloped roof area, then into roofing squares and shingle bundles. Enter your measurements and the result updates as you type — there is nothing to submit and nothing to wait for.
Everything runs in your browser. Nothing you enter is sent to a server, there is no sign-up, and there is no usage limit.
Who it's for
Homeowners pricing a re-roof and contractors checking a supplier quote.
How the calculation works
roof area = footprint × √(1 + (rise ÷ 12)²); squares = area ÷ 100; bundles = squares × 3
The result depends on a few standard constants, which are stated on the page rather than hidden:
- The pitch multiplier is the true slope factor: a 6/12 roof is 1.118× its footprint, a 12/12 roof 1.414×.
- One "square" is 100 ft² of roof; standard 3-tab shingles come 3 bundles to the square.
- Footprint is treated as a simple rectangle — add each section separately for an L-shaped or complex roof.
- Hips, valleys and ridge cap are not itemised; the waste allowance is where they are absorbed.
Getting an accurate estimate
Measure twice. Small errors in a linear dimension compound, because material volume scales with two or three of them at once — a 6-inch error across a 20-foot run is over a cubic foot of material on a 4-inch pour.
Keep the waste allowance. The default is deliberately conservative: offcuts, spillage, uneven sub-base and breakage are all real, and running short mid-job usually costs more in a second delivery than the surplus did.
Round up when you order. Suppliers sell in fixed increments — quarter yards, whole bags, full boxes — so treat the figure here as the minimum you need rather than the exact amount to buy.