Carpet Area / Built-up Area Calculator
Convert between carpet area (the actual usable floor space, as defined under RERA), built-up area and super built-up area, using editable wall and common-area loading percentages that reflect your specific project.
Carpet Area & Loading Factors
Loading percentages vary by project and building design -- 12-20% for wall/balcony loading and 15-30% for common area loading are commonly seen ranges. Check your project's RERA filing or builder's brochure for the exact figures used.
Results
Built-Up Area
Super Built-Up Area
How This Calculator Works
RERA (the Real Estate (Regulation and Development) Act) legally defines carpet area as the net usable floor area within a unit's walls -- the space you can actually put furniture on. Built-up area adds the thickness of the walls themselves plus balconies, and super built-up area (sometimes called "saleable area") further adds a proportional share of common areas like lobbies, staircases and lifts. This calculator applies your entered loading percentages to convert carpet area into both larger figures.
Why Builders Quote Super Built-Up Area
Since RERA came into effect, builders are required to clearly state the carpet area in their agreements, but pricing per square foot is still commonly discussed in terms of super built-up area, which appears larger (and so the quoted rate per sq ft appears lower) than carpet-area-based pricing. Understanding the loading percentage between the two figures helps you compare listings that use different area bases fairly.
Why the Loading Percentages Are Editable
There's no single national standard for wall/balcony loading or common area loading -- both depend on the building's design, the number of floors, amenities provided and the developer's own conventions. Always check your specific project's RERA filing (available on your state's RERA website) for the actual carpet area and any stated loading factor, rather than relying solely on generic defaults.
Is my data sent to any server?
No. Every calculation happens directly in your browser using JavaScript. Nothing you enter is ever transmitted to OurPaisa Tools' servers or stored anywhere -- close the tab and it's gone.
Disclaimer: This tool provides a general estimate based on the loading percentages you enter, for informational purposes only. It does not constitute legal advice on RERA compliance or an official area certification. Always verify actual carpet, built-up and super built-up area figures against your project's RERA filing and builder-buyer agreement. See our Disclaimer and Terms of Use for more detail.