Work out built up area instantly with clear inputs, formula shown and shareable results.
Carpet area is the usable floor inside the walls. Built-up area adds the wall thickness and balconies, typically about ten percent more. Super built-up area then adds a share of lobbies, stairs, lifts and services, the loading factor, which is why the area quoted in a sales brochure is well above what can be furnished.
Built-up area
Built-up = carpet x (1 + wall allowance) + balcony
Super built-up
Super built-up = built-up x (1 + common area loading)
Built-up = carpet x (1 + wall allowance) + balcony. Carpet area is the usable floor inside the walls.
Carpet area, because it is the only one with a consistent definition. A quoted rate per square foot on super built-up area can hide a loading factor anywhere from 15 to 50 percent.
This calculator takes 4 inputs: Carpet area, Wall and duct allowance, Balcony and terrace area, Common area loading. The pre-filled defaults are a realistic worked example — replace them with your own site or project figures.