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Roof Area Calculator

Calculate the actual roof area based on floor plan and roof pitch

m²
°
🇩🇰 All calculations are based on Danish rules, rates, and currency (DKK). This calculator is translated for convenience but applies exclusively to Denmark.

Calculate your roof area

Our roof area calculator helps you determine the actual roof area from the floor plan and pitch. The actual roof area is always larger than the floor plan because the roof surface slopes.

Roof pitch

Roof pitch is measured in degrees. A flat roof is 0-5°, a low pitch 15-25°, normal 25-45°, and steep over 45°. Most Danish houses have 25-35° pitch. A 30° pitch increases the area by about 15%.

What is roof area used for?

The roof area is important for ordering roof tiles, sheets, underlayment or insulation. It's also used for solar panel calculations and insurance.

Frequently Asked Questions

How much larger is the roof area than the floor plan?

It depends on the roof pitch. At 15° the roof area is about 4% larger. At 30° about 15% larger. At 45° about 41% larger. The steeper the roof, the greater the difference.

What is the typical roof pitch in Denmark?

Most Danish houses have a roof pitch of 25-35°. Newer houses may have lower pitch (15-20°). Older timber-framed houses can have up to 45-50°. Flat roof is defined as under 5°.

Should I include the overhang?

Yes, for accurate calculation you should include the overhang, typically 30-50 cm around the house. Add the overhang to the floor plan dimensions before calculating.

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