Ask two developers for the "area" of a similarly priced flat and you can get two very different numbers, not because either one is lying, but because "area" in Indian real estate can legally mean three different things. Understanding the difference is the single most useful piece of arithmetic a buyer can do before comparing two projects.
Carpet area: what you actually get to use
Carpet area is the actual usable floor space inside a flat, measured wall to wall — literally the area you could cover with a carpet. It excludes the thickness of the walls themselves, balconies in most legal definitions, and any shared spaces outside your front door. This is the number that tells you, most honestly, how much living space you're buying, and it's the figure RERA requires every registered project to disclose and price against.
Built-up area: carpet area plus your own walls
Built-up area adds the thickness of the walls enclosing your flat, and typically the area of any attached balcony, to the carpet area. As a rough rule of thumb, built-up area runs about 110–120% of carpet area — so a flat with 1,000 sq ft of carpet area might show a built-up figure somewhere around 1,100–1,200 sq ft. This is a legitimate, commonly used measure, but it's already larger than the space you can actually furnish.
Super built-up area (saleable area): your share of the whole building
Super built-up area — often called saleable area — goes a step further and adds a proportionate share of common areas: lobbies, staircases, lift shafts, corridors, and sometimes amenity spaces like a clubhouse or garden. This is typically 140–170% of carpet area or more, depending on how amenity-heavy the project is and how the developer apportions common space across units. Two projects with identical carpet area can show very different super built-up figures simply because one has a larger clubhouse or wider corridors to apportion.
The "loading factor" in one line
The gap between carpet area and whichever larger figure is being quoted is called the loading factor, usually expressed as a percentage. A 25% loading factor means the quoted area is 25% larger than the actual carpet area; loading factors across the market commonly range from roughly 25% to 60%, depending on the project and how it defines built-up or super built-up area. Knowing the loading factor lets you back-calculate the real carpet area from any quoted figure.
A side-by-side comparison
| Measure | What it includes | Typical range vs. carpet area |
|---|---|---|
| Carpet area | Usable space within the walls only | 100% (the baseline) |
| Built-up area | Carpet area + wall thickness + balcony | ~110–120% |
| Super built-up / saleable area | Built-up area + proportionate share of common areas | ~140–170%+ |
Why this makes comparing two projects tricky
If Project A quotes ₹1 crore for 1,000 sq ft of carpet area, and Project B quotes ₹1 crore for 1,000 sq ft of super built-up area, Project B is meaningfully more expensive per square foot of actual living space — its real carpet area at that price might only be 600–700 sq ft. Unless you know which area measure each price is based on, the two quotes aren't comparable at all, and the "cheaper" option on paper can easily be the more expensive one in practice.
Always ask one specific question before comparing prices across projects: "is this price quoted per carpet area, built-up area, or super built-up area?" The answer changes the real price per square foot more than almost anything else in the negotiation.
