Buying a property, especially in India, involves navigating a maze of technical terms like Carpet Area, Built-up Area, and Super Built-up Area. Before the Real Estate (Regulation and Development) Act, 2016 (RERA), there was no standard definition for the area of an apartment, leading to confusion and often unfair practices where buyers paid for the ‘Super Built-up Area’ but received much less usable space.
The RERA Carpet Area Calculator helps you determine the exact ‘Net Usable Area’ of a property as per the official government definition. By inputting room dimensions, it calculates the compliant Carpet Area, estimates the Built-up and Super Built-up areas based on standard assumptions, and even projects the property cost. This tool is essential for homebuyers to ensure they get what they pay for.
What is RERA Carpet Area?
According to the RERA Act, **Carpet Area** is defined as the net usable floor area of an apartment, excluding the area covered by the external walls, areas under services shafts, exclusive balcony or verandah area, and exclusive open terrace area, but including the area covered by the internal partition walls of the apartment.
Simply put:
• Included: Bedrooms, Living Room, Kitchen, Bathrooms, Internal Partition Walls.
• Excluded: External Walls, Balconies, Verandahs, Terraces, Common Areas (Lifts, Corridors, Lobbies).
The RERA Carpet Area Formula
The calculation is straightforward but specific:
| RERA Carpet Area = (Net Usable Area of Rooms) + (Area of Internal Walls) |
Where:
• Net Usable Area = Sum of (Length × Width) of all rooms.
• Internal Walls = Area occupied by the footprint of walls separating rooms within the flat.
Carpet vs. Built-up vs. Super Built-up Area
| Term | Definition |
| Carpet Area (RERA) | Net usable space + Internal walls. The actual area you can use. |
| Built-up Area | Carpet Area + External Walls + Balconies + Service Shafts. |
| Super Built-up Area | Built-up Area + Proportionate share of Common Areas (Lobbies, Staircases, Lifts, Amenities). |
Features of Our RERA Calculator
• **Room-by-Room Breakdown:** Add multiple rooms (Living, Kitchen, Bedroom) with individual dimensions to get precise net area.
• **Internal Wall Options:** Choose between an auto-estimate (standard 5% of net area) or enter exact manual measurements if available.
• **Comprehensive Output:** Instantly sees the breakdown of RERA Area, Built-up Area, and Super Built-up Area.
• **Cost Estimation:** Input the ‘Loading Factor’ and ‘Price per Sq Ft’ to estimate the total property cost based on Super Built-up Area.
• **Visual Guide:** A dynamic bar chart visualizes the proportion of usable space versus common areas and walls.
How to Use This Calculator
1. **Add Rooms:** Enter the name, length, and width for each room in your apartment plan.
2. **Internal Walls:** Select ‘Auto’ for a quick estimate or ‘Manual’ to enter the specific area occupied by internal walls.
3. **Add Exclusions:** Enter the area of Balconies or Verandahs separately, as these are part of the Built-up area but not RERA Carpet area.
4. **Project Settings:** Enter the ‘Loading Factor’ (usually 25-30%) and the Price per Sq Ft quoted by the builder.
5. **Analyze:** Review the calculated RERA Area and the estimated Total Cost to make an informed decision.
Frequently Asked Questions (FAQs)
Q: Why is RERA Carpet Area important?
A: It is the only legally binding area definition for property sales in India. Builders must quote prices based on RERA Carpet Area, ensuring transparency.
Q: What is a Loading Factor?
A: The Loading Factor is a multiplier applied to the Carpet Area to account for common spaces (corridors, lifts, clubhouse). It typically ranges from 20% to 40%. A higher loading factor means you pay for more ‘unusable’ space.
Q: Are balconies included in RERA Carpet Area?
A: No. Under RERA, balconies and verandahs are excluded from the Carpet Area definition, although they are part of the detailed plan.
Q: Can I use this for commercial properties?
A: Yes, the principle of Net Usable Area vs. Super Built-up Area applies to commercial offices and shops as well.
Tips for Home Buyers
• Always ask the builder for the breakdown of the RERA Carpet Area versus the Super Built-up Area.
• Measure the rooms yourself if possible, or verify them against the sanctioned architectural plan.
• Be wary of high loading factors (>35%); it implies a significant portion of your money is going towards common areas rather than your private living space.
