Construction

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Calculatrice: Roofing.

Utilisez Calculatrice: Roofing pour obtenir un résultat clair et pratique à partir de vos données.

On-device calculationNo signup
01

Set your values

Results update as you type.

planArea: 200

planArea

200.00
slopedArea: 223.61

slopedArea

223.61
materialArea: 245.97

materialArea

245.97
roofingSquares: 2.46

roofingSquares

2.46
wastePercent: 10

wastePercent

10.00

Outputs use your entered dimensions and an explicit waste percentage; no material density is inferred.

FAQs

What are roofing squares?

One roofing square is conventionally 100 square feet of roof surface. Local products and installation details can require additional material.

Cite this calculator

Canonical URL: https://mathify.one/fr/construction/roofing

Cite as: Mathify. (2026). Calculatrice: Roofing. https://mathify.one/fr/construction/roofing

Use Cases

Estimate roofing material needs

Quickly determine the amount of shingles or other roofing materials needed for a project, helping with budgeting and ordering.

Example: A 30ft x 40ft roof with a 6/12 pitch yields approximately 1,440 sq ft of surface area.

Compare roof pitches for cost planning

See how different pitch values affect the total roof area and material quantities, aiding in design decisions.

Example: Increasing pitch from 4/12 to 8/12 increases the surface area by about 20%.

Frequently Asked Questions

How does the roofing calculator estimate roof area?
The calculator uses the plan dimensions (length and width) and the roof pitch to calculate the actual surface area. It accounts for the slope factor, which increases the area compared to the flat plan area.
What units does the roofing calculator support?
The calculator supports common units for plan dimensions (feet, meters, etc.) and pitch (rise per 12 inches or degrees). The results are provided in square feet or square meters, and material units like bundles or squares.
Can I use this calculator for any roof type?
This calculator is designed for simple gable or shed roofs with a uniform pitch. For complex roofs with multiple planes, valleys, or hips, you may need to calculate each section separately and sum the results.

Tips & Common Mistakes

Tips

  • Measure the plan dimensions accurately from the building footprint, not the sloped surface.
  • For pitch, use the rise over a 12-inch run (e.g., 6/12) or the angle in degrees.
  • Always add 10-15% extra material for waste, cutting, and overlaps.
  • If your roof has multiple sections, calculate each separately and sum the totals.

Common Mistakes to Avoid

  • Using the sloped length instead of the plan length when entering dimensions.
  • Forgetting to convert pitch to the same unit system as the dimensions.
  • Not accounting for overhangs or eaves, which increase the actual roof area.

Last updated: August 13, 2026