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Carpet Area Calculator

Easily convert and understand the difference between Carpet Area, Built-up Area, and Super Built-up (Saleable) Area.

Sq. Feet
Sq. Meters

Base Property Area

Loading Factors

Standard is 10-15% of Carpet Area

Standard is 20-30% of Built-up Area

Area Expert Tips

1
What is Carpet Area?

This is the actual usable floor area inside your apartment walls where you can literally "lay a carpet". It excludes external walls and balconies.

2
What is Built-up Area?

Built-up Area = Carpet Area + Thickness of inner and outer walls + Balcony. It is usually 10% to 15% larger than the carpet area.

3
Super Built-up (Saleable) Area

This adds common amenities (lobbies, stairs, lifts, clubhouses) proportionately to your flat. Builders charge you based on this number!

Enter your carpet area to see exactly how much you are paying for walls and common spaces.

The Ultimate Carpet vs Built-Up Area Calculator for India (2026-2027)

Navigating the real estate market in India can be confusing, especially when developers throw around terms like Carpet Area, Built-Up Area, and Super Built-Up Area. Understanding these metrics is vital because you use the Carpet Area, but you pay for the Super Built-Up Area. Our Area Calculator clarifies this confusion by showing you exactly how much space is consumed by walls, common areas, and amenities, giving you absolute transparency into what you are actually buying.

How to Calculate Property Areas (Step-by-Step)

  • Enter Base Area: Input your known Carpet Area in square feet or square meters. This is usually listed in your RERA documentation.
  • Define Wall Loading: Enter the percentage of space taken up by internal and external walls. The industry standard is typically between 10% and 15%.
  • Define Common Area Loading: Enter the percentage added for common amenities (lobbies, lifts, staircases). This usually ranges from 20% to 30%.
  • View Breakdown: Click calculate to see the precise jump from Carpet Area to Built-Up Area, and finally to the Super Built-Up (Saleable) Area.

Engineering Formulas & Thumb Rules for Property Areas

The mathematical relationship between these areas is linear but compounding. The formula starts with the Carpet Area (the net usable floor area). Built-Up Area = Carpet Area + Wall Thickness Area + Balcony Area. Generally, this adds 10-15% to the Carpet Area. Then comes the Super Built-Up Area = Built-Up Area + Proportionate Share of Common Areas. Builders apply a "Loading Factor" (usually 25%) to the Built-Up Area to arrive at the final Saleable Area. For example, a 1,000 sq.ft. Carpet Area might become an 1,150 sq.ft. Built-Up Area, which then becomes a 1,437 sq.ft. Super Built-Up Area.

Current Market Rates in India & 2027 Projections

  • Average Loading Factor (Affordable Housing): 20% - 25%
  • Average Loading Factor (Luxury Condos): 30% - 40% (Due to larger clubhouses, wide lobbies)
  • RERA Carpet Area Standard: Excludes external walls, includes internal partition walls.
  • Construction Cost (Built-Up Area basis): ₹1,600 - ₹2,200 per sq.ft
  • Real Estate Pricing: Almost always quoted on Super Built-Up (Saleable) Area.

Frequently Asked Questions (FAQ)

What exactly does RERA define as Carpet Area?

Under the Real Estate (Regulation and Development) Act, Carpet Area is defined as the net usable floor area of an apartment. It excludes the area covered by external walls, services shafts, exclusive balcony or verandah area, and exclusive open terrace area, but includes the area covered by the internal partition walls of the apartment.

Why do builders charge based on Super Built-Up Area?

Builders construct entire complexes, including lobbies, staircases, lifts, gyms, and clubhouses. The cost of constructing and maintaining these common areas is divided proportionately among all flat owners and added to their individual flat size as a "loading factor."

Is a lower loading percentage always better?

Generally, yes, because you get more usable space inside your home for the price. However, ultra-luxury projects often have higher loading percentages (35-40%) because they offer extensive, sprawling common amenities like massive clubhouses, multiple pools, and grand entrance lobbies.

Can I negotiate the loading factor?

You cannot negotiate the mathematical loading factor itself, as it is determined by the building's architectural design. However, being aware of it allows you to compare two different projects effectively and negotiate the per-square-foot base rate with the developer.