What this guide covers
When you buy a flat, you will hear three different numbers for its size. The builder’s brochure talks about super built-up area, the RERA agreement mentions carpet area, and someone at the registration office may ask for built-up area. They are not the same, and the one you multiply by circle rate can change your stamp duty by over a lakh of rupees.
Carpet, built-up and super built-up area
- Carpet area: the floor area you can actually use inside your flat, measured wall to wall. Under RERA, it leaves out the outer walls, service shafts and your exclusive balcony or terrace.
- Built-up area: the carpet area plus the thickness of the walls, and often the balcony. It is usually around 10% to 20% more than the carpet area.
- Super built-up area: the built-up area plus your share of the common areas, such as the lobby, staircase, lifts and clubhouse. This is the biggest number, and the one builders often quote in ads.
So for the same flat, you might see 650 sq ft carpet, 750 sq ft built-up and 950 sq ft super built-up.
Which area is used for circle rate?
There is no single rule for all of India. Each state’s rate schedule or guidelines say which area to use.
- Some states, like Maharashtra, apply circle rate to built-up area. If your agreement shows only carpet area, the guidelines tell you to multiply it by a set factor, 1.1 or 1.2 depending on the area and year, to get the built-up area.
- Other states simply use the area written in the sale deed.
- Super built-up area is almost never used, because it includes space that is not part of your flat.
Before you calculate, ask the Sub-Registrar office or your lawyer which area they will use for your property.
How much difference does it make?
Here is a real example. In zone 29/166 of Bandra East, Mumbai, circle rate for flats is ₹1,99,380 per sq m. Suppose your flat has a carpet area of 50 sq m (about 538 sq ft).
- On carpet area: 50 × ₹1,99,380 = about ₹99.7 lakh.
- On built-up area, supposing a factor of 1.2: 60 sq m × ₹1,99,380 = about ₹1.2 crore.
That is a difference of about ₹20 lakh in circle rate value. At 6% stamp duty, it changes the minimum stamp duty by about ₹1.2 lakh.
If your deal price is higher than both figures, it makes no difference, because stamp duty is charged on your price. The area basis matters most when your price is close to circle rate value.
Floor and age can also change the value
In some states, circle rate value of a flat is adjusted after you multiply the rate by the area. For example:
- Flats on higher floors in buildings with a lift may be valued a little higher.
- Upper floor flats in buildings without a lift may be valued lower.
- Older buildings may get a reduction for their age, if you can show proof such as the occupancy certificate or old tax bills.
These rules are different in each state and can change from year to year. Your lawyer or the Sub-Registrar office can tell you if any apply to your flat.
How to calculate the value of your flat
- Find circle rate for your zone and use the rate for flats. Our guide on how to read circle rates shows you how.
- Check which area your state uses: carpet, built-up or the area in the deed.
- If you need built-up area and only have carpet area, use the conversion factor your state gives.
- Make sure the area and the rate are in the same unit. The area converter can help.
- Multiply the rate by the area with the property value calculator.
- Compare the result with your deal price. Stamp duty is charged on the higher of the two.
Carpet vs built-up area: common questions
Is circle rate applied to carpet area or built-up area?
It depends on the state. Some, like Maharashtra, apply the rate to built-up area and convert carpet area using a set factor. Others use the area written in the sale deed. Ask the Sub-Registrar office which one they use in your area.
What is the difference between carpet area and built-up area?
Carpet area is the usable floor area inside the walls of your flat. Built-up area adds the thickness of the walls and, in many cases, the balcony. So built-up area is always a little more than carpet area.
Can super built-up area be used for circle rate?
Usually not. Super built-up area includes your share of the lobby, stairs, lifts and other common areas, so it is much bigger than the flat itself. Using it would make the value too high.
Does changing sq ft to sq m change carpet area into built-up area?
No. Converting the unit only changes how the same area is written. 1,000 sq ft of carpet area is still carpet area when you write it as 92.9 sq m.
Which area is written in my sale agreement?
For new flats in RERA registered projects, the builder must state the carpet area in the agreement. Older agreements and resale deeds may mention built-up or super built-up area instead, so read it carefully.