Carpet Area Calculator: Carpet, Built-up and Super Built-up Area
Enter the area the builder quotes, choose what it is, and set the wall share and loading. You see carpet, built-up and super built-up area and how much of what you pay for is usable.
- Nothing you type is stored
- Free
- No signup
Carpet area
802.7sq ft
- Carpet area
- 802.7 sq ft
- Built-up area
- 923.1 sq ft
- Super built-up area
- 1,200 sq ft
- Usable share (carpet ÷ super built-up)
- 66.9%
Under RERA, flats are sold on carpet area. Ask for it in writing.
Show working
- 802.7 × 1.15 = 923.1 sq ft
- 923.1 × 1.3 = 1,200 sq ft
How to use
- Choose whether your number is carpet, built-up or super built-up area.
- Enter the area and adjust walls % and loading %.
- Optionally enter the price per sq ft to see the effective price on carpet area.
Good to know
Under RERA (Real Estate (Regulation and Development) Act 2016, section 2(k)), carpet area is the net usable floor area of a flat, excluding external walls, service shafts, exclusive balcony or verandah and exclusive open terrace, but including internal partition walls. Since RERA, builders must sell on carpet area.
Built-up area adds the walls (and often balconies) to carpet area, typically 10–20% more. Super built-up area adds a share of common areas such as lobby, stairs, lift and clubhouse; this “loading” is commonly 25–40% in Indian apartments.
Here built-up = carpet × (1 + walls %) and super built-up = built-up × (1 + loading %). Builders define loading differently, so ask for the carpet area in writing (it must be in the RERA agreement) instead of relying on these estimates.
Questions
What is carpet area under RERA?
The net usable floor area inside the flat, including internal walls but excluding external walls, shafts, exclusive balcony/verandah and open terrace (RERA Act 2016, section 2(k)).
How do I convert super built-up to carpet area?
Divide by (1 + loading) and then by (1 + walls). 1,200 sq ft with 30% loading and 15% walls gives about 803 sq ft carpet.
What loading is normal?
Often 25–40% in apartments; higher with big clubhouses and amenities. Check the builder’s figure.
What is the real price per sq ft?
Price on super built-up × super built-up ÷ carpet. At ₹6,000 on 1,200 sq ft with 803 sq ft carpet, the real rate is about ₹8,970 per sq ft of carpet.
Is balcony part of carpet area?
Under RERA, an exclusive balcony is not part of carpet area; it is listed separately.