Mansard Roof Square Footage

The Mansard Roof Square Footage Calculator is designed to accurately calculate the total square footage of a Mansard-style roof using imperial measurements. Users can input the building dimensions, eaves overhang, and slopes of both the upper and lower roofs to obtain precise results.

What is a Mansard Roof?

A Mansard or French or curb roof is a four-sided gambrel-style hip roof with two slopes on each side. The lower slope is steeper than the upper slope, which is usually almost flat. This design maximizes the interior space of the attic and provides an elegant aesthetic.

Calculator

1. enter the length of the building in feet and inches
2. the width of the building in feet and inches
3. the eave overhang in inches
4. the upper roof pitch as a ratio (e.g., 2 for a 2/12 pitch)
5. the lower roof pitch as a ratio (e.g., 9 for a 9/12 pitch)
6. enter the lower roof length in feet and inches

Results

1. the surface area of the lower section of the Mansard roof in square feet (this is the area that covers the four lower-pitched sides of the roof)
2. the angle of the lower section of the roof in degrees (this represents the steepness of the lower roof's slope)
3. the slope of the lower roof expressed as a percentage.
4. the perimeter of the lower roof in lineal feet
5. the combined length of the four lower roof hips in lineal feet
6. the surface area of the upper section of the Mansard roof in square feet (this covers the relatively flatter upper part of the roof)
7. the angle of the upper section of the roof in degrees
8. the slope of the upper roof expressed as a percentage
9. the perimeter of the upper roof in lineal feet
10. the combined area of the upper and lower roofs in square feet
11. And in case the upper roof is not flat:
    the additional ridge length for an upper gable roof in lineal feet
12. the length of the four hip ridges for a hip upper roof in lineal feet