Daily · Free tool
Carpet ↔ Built-up Converter
Carpet area = usable floor space. Built-up = carpet + walls (~10-15% extra). Super built-up = built-up + common areas (~20-30% extra). RERA mandates carpet-only quoting since 2017.
Typically 10-15%
Typically 20-30%
RERA Act 2016: builders must quote carpet area only. Compare carpet ÷ super built-up to spot "loaded" quoting (lower carpet = poorer value).
How it works
We apply the two standard Indian conversion factors. Built-up = carpet × (1 + wall factor), typically 10–15% extra for walls, columns and the balcony slab. Super built-up = built-up × (1 + loading factor), where loading is the share of common areas (lobby, lift, club, staircase) allocated to your flat — usually 20–30% in metros and as high as 40% in luxury townships with big amenities.
Worked example
A 2BHK in Wakad, Pune marketed as “1,200 sqft super built-up” at ₹7,500/sqft costs ₹90 lakh. At 25% loading the built-up is 960 sqft, and at 12% wall factor the actual carpet is ~857 sqft. Real ₹/sqft on usable space is ₹10,500 — 40% higher than the headline number. RERA (Real Estate Regulation Act, 2017) now mandates carpet-only quoting in agreements, but brochures still lead with super built-up.
When to use this
- Comparing two flats in Gurgaon or Bengaluru where one quotes carpet and the other super built-up
- Cross-checking the agreement (carpet) against the brochure (super built-up) before signing
- Estimating loading factor across DLF, Lodha, Prestige or Sobha launches
Once you know the carpet area, plug it into the construction cost estimator or the EMI calculator to size the loan correctly.
FAQ
Why is my flat smaller than what I paid for?
You probably paid on super built-up. Walls (10-15%) + amenity loading (20-30%) means actual usable space is 30-40% less than the marketed number. RERA Act 2016 mandates carpet-area-only quoting since 2017.
What counts as "common amenity"?
Lobby, staircase, lift, club house, gym, swimming pool, rooftop, garden — spread across all flats by their proportional share. Higher loading = more amenities (or just inefficient layout).
Difference between built-up and saleable area?
Saleable = built-up + private balcony / private terrace. Some builders bundle balcony into built-up; check the agreement. Super built-up is built-up + amenity share.