Work out carpet area vs built up area instantly with clear inputs, formula shown and shareable results.
Carpet area is the usable floor you can actually lay carpet on, built-up area adds walls and balconies, and super built-up adds a share of lifts, lobbies and amenities. The carpet-to-super-built-up ratio is typically 65-75%, and it is the only honest basis for comparing quoted prices.
Area definitions
carpet = built-up x (1 - wall share) - balcony allowance; super built-up = built-up x (1 + loading)
Carpet area. Loading factors vary between developers, so a lower price per super built-up foot can be worse value per usable foot.
20-30% is common; above 40% suggests very generous common areas or an aggressive sales practice. Many jurisdictions now require carpet area disclosure.