Calculate the area of a mansard roof — a four-sided gambrel with steep walls on all sides and a flat or low-slope top, creating maximum usable upper-floor space.
Enter building footprint dimensions
A mansard roof is a four-sided gambrel — steep walls on all four sides with a flat or nearly-flat top. Named after French architect François Mansart, this design creates a full usable upper story within the roof structure. The steep lower slopes are typically 70° and often feature dormer windows.