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Carpet, built-up & super built-up area calculator
Convert between carpet, built-up and super built-up area, and understand what you actually pay for.
Carpet, built-up and super built-up, explained
Carpet area is the usable floor space. Built-up area adds the walls, usually 10 to 20 percent more. Super built-up area adds a share of common areas, the loading, usually 25 to 40 percent. Always confirm the carpet area in your agreement.
A worked example
Take a flat with a carpet area of 1,000 sq ft. At a 15 percent wall factor the built-up area is about 1,150 sq ft. At a 30 percent loading factor the super built-up area is about 1,495 sq ft. You would typically be quoted on the super built-up figure, so the rate per square foot looks lower than it really is against the space you can actually use.
| Measure | What it includes | Example |
|---|---|---|
| Carpet area | The usable floor inside your walls. What you can actually furnish. | 1,000 sq ft |
| Built-up area | Carpet plus the walls, and usually the balcony. Commonly 10 to 20 percent more. | ~1,150 sq ft |
| Super built-up area | Built-up plus a share of common areas: lobby, stairs, lift, sometimes amenities. Commonly 25 to 40 percent more. | ~1,495 sq ft |
Why the loading factor is the number to ask about
Two flats advertised at the same price per square foot are not comparable unless you know the loading. A 25 percent loading and a 40 percent loading on the same carpet area produce very different quoted sizes, and the higher loading quietly makes a worse deal look cheaper. The reliable way to compare two options is to divide the total price by the carpet area, not by the super built-up area, and compare those two numbers instead.
Loading is not a regulated figure, which is precisely why it varies between builders and projects. Ask for it explicitly, in writing, as a percentage.
What to check in the agreement
- The carpet area, stated as a number. Under RERA this is the figure that must be disclosed
- The loading percentage used to arrive at the quoted size
- Whether balconies, utility areas and terraces are inside or outside the carpet figure
- Whether the price is quoted on carpet or super built-up area
- The tolerance clause, meaning what happens if the delivered area differs from the agreed area
Frequently asked questions
Which area am I actually paying for?
In practice, usually the super built-up area, which is why the headline rate per square foot can look attractive. What you live in is the carpet area. Compare options on price per carpet square foot to see which is genuinely better value.
Is the loading factor capped by law?
No. It is a commercial figure set by the developer, which is why it differs so widely. RERA requires carpet area to be disclosed, which is the protection that matters, but it does not fix loading at a particular percentage.
Does any of this apply to an independent house?
Less so. Loading exists because apartment buyers share common areas. If you are building your own house on your own plot, the figure that matters is built-up area, because that is what construction is priced on. See the construction cost calculator.