West Bengal's valuation tool for flats asks for carpet, built-up and super built-up area, and the market value it computes decides whether you pay duty on your price or on a higher assessed figure. Official guidance and recent commentary disagree on which area drives that value, so enter figures that match your agreement and RERA papers, and read the result on the e-Assessment slip.
A Kolkata builder quotes ₹4,500 per square foot on a 1,000 sq ft "saleable" flat. The RERA-registered carpet area is 750 sq ft. The portal's flat tool has boxes for both, plus a third for built-up area. Which number goes where, and does it change the stamp duty? The answer decides whether the e-Assessment slip lands near your price or well above it.
This guide explains the three area measures, what is and is not settled about how West Bengal values flats, and how to avoid the most common area-related errors at registration.
Quick answer (2026): Stamp duty is 6% up to ₹1 Crore and 7% above in municipal and corporation areas (5% and 6% in panchayat areas), plus about 1% registration fee, charged on the higher of your agreement value and the assessed market value. The department's older FAQ says super built-up area is used for flats. Some 2026 commentary says registration follows carpet area. The portal's flat form asks for all three. We could not find a notification that settles it, so verify against your slip.
- Carpet, built-up and super built-up area explained
- What West Bengal actually says about area
- Where RERA fits in
- Rates and thresholds
- How to enter area in the portal, step by step
- Worked examples: when area matters and when it does not
- Other documents and tax savings
- Documents checklist and common area errors
- Frequently asked questions
1. Carpet, Built-Up and Super Built-Up Area Explained
Three measures appear in Kolkata flat marketing and paperwork.
| Measure | What it includes | Typical size relative to carpet area |
|---|---|---|
| Carpet area | The net usable floor area inside the flat walls, excluding external walls and balconies | 100% (baseline) |
| Built-up area | Carpet area plus the thickness of the walls and balconies or terraces | About 110% to 115% |
| Super built-up area | Built-up area plus a proportionate share of common areas such as lobbies, stairs and lifts | About 125% to 140% |
The gap between super built-up and carpet area is called the loading. It varies by project, which is why two flats with the same super built-up area can have very different usable space.
Marketing materials in Kolkata still lean on super built-up area, because it is the biggest number. That is a pricing convention, not a legal measure of what you own.
2. What West Bengal Actually Says About Area
This is the question buyers ask most, and it needs a careful answer.
What the official sources show
- The registration department's own FAQ, in an older version, said that for assessing the true market value of a flat or apartment, super built-up area is taken into account.
- The valuation rules for flats, as summarised by legal commentators, refer to the super built-up area in square feet for the flat being valued, and provide that an old flat's value is depreciated for age.
- The department's Market Value of Flat/Apartment tool today asks for carpet area, covered or built-up area and super built-up area, along with the use of the flat and the floor type.
What recent commentary says
- Several 2026 guides say that West Bengal registration moved to carpet area in line with RERA, so that duty on flats now follows carpet rather than super built-up area. One places the change at January 2024.
What we could not confirm
We did not find a current notification that states, in terms, that West Bengal assesses flat market value on carpet area alone. The older official FAQ points the other way, and the portal asks for all three measures. Both positions cannot be fully right, and the portal's behaviour for your specific flat is what counts.
How to use this: Do not budget on a rule you read in a blog. Run the valuation with your agreement figures, read the e-Assessment slip, and if the number moves a lot when you change the area basis, ask the Sub-Registrar which area the assessment relied on.
3. Where RERA Fits In
The Real Estate (Regulation and Development) Act, 2016 requires promoters to quote and sell on carpet area, which the Act defines as the net usable floor area, excluding external walls, services shafts, exclusive balcony and open terrace areas, but including the area covered by internal partition walls. West Bengal's real estate regulator oversees registered projects in the state.
For a buyer this has three practical consequences.
- Your agreement for sale should state the carpet area. If it quotes only super built-up area, ask the builder for the RERA-registered carpet area in writing.
- The price per square foot can differ by basis. A builder quoting on super built-up area and a competitor quoting on carpet area are not comparable until you convert.
- The stamp duty value is a separate calculation. RERA governs how the flat is sold. The registration department separately decides how it is valued for duty.
4. Rates and Thresholds
| Area | Up to ₹1 Crore | Above ₹1 Crore | Registration fee |
|---|---|---|---|
| Municipal, corporation and notified areas | 6% | 7% | About 1% |
| Panchayat areas | 5% | 6% | About 1% |
- No gender-based rebate applies in West Bengal.
- The 2% rebate and 10% market-value cut ended on 30 June 2024.
- Duty is charged on the higher of the agreement value and the assessed market value.
5. How to Enter Area in the Portal, Step by Step
The tool is on wbregistration.gov.in.
- Open the Market Value of Flat/Apartment tool.
- Select the district and locality of the flat.
- Enter the carpet area, covered or built-up area and super built-up area from your documents. Use your RERA registration for carpet area and the agreement for the others.
- Select the use of the flat (residential or commercial) and the floor type.
- Enter the building's age and features the form asks about, such as a lift or parking.
- Note the computed value, then repeat the exercise with the calculation assistance tool for duty and fee.
- File the e-Requisition only when the figures are consistent across the agreement, the RERA record and your inputs. The e-Assessment slip shows the duty and fee and carries a 14-digit query number and year.
- Pay through GRIPS. Online payment is allowed once duty exceeds ₹5,000 and is compulsory at ₹5 Lakhs or more.
Before you pay: Test your scenario on StampDutyCalc.in with your price and your carpet and super built-up figures. If the planning number and the slip differ, the difference points you to the input to recheck.
6. Worked Examples: When Area Matters and When It Does Not
The key to the area question is the higher-of rule. A different area basis changes your bill only when it pushes the assessed value above your agreement price. The assessed rates below are hypothetical and used for illustration only.
Example A: ₹45 Lakh flat in a municipal area
Agreement value ₹45,00,000. Flat has 1,000 sq ft super built-up area and 750 sq ft carpet area. Assume a hypothetical assessed rate of ₹4,800 per sq ft.
| Basis for assessed value | Assessed value | Value charged (higher of) | Stamp duty (6%) | Registration fee (1%) | Total |
|---|---|---|---|---|---|
| Super built-up (1,000 sq ft) | ₹48,00,000 | ₹48,00,000 | ₹2,88,000 | ₹48,000 | ₹3,36,000 |
| Carpet (750 sq ft) | ₹36,00,000 | ₹45,00,000 (agreement) | ₹2,70,000 | ₹45,000 | ₹3,15,000 |
The basis changes the bill by ₹21,000 here. On the carpet basis the agreement value is higher, so it governs.
Example B: ₹1.2 Crore flat in a municipal area
Agreement value ₹1,20,00,000. Flat has 1,600 sq ft super built-up and 1,200 sq ft carpet area. Assume a hypothetical assessed rate of ₹8,000 per sq ft.
| Basis for assessed value | Assessed value | Value charged (higher of) | Stamp duty (7%) | Registration fee (1%) | Total |
|---|---|---|---|---|---|
| Super built-up (1,600 sq ft) | ₹1,28,00,000 | ₹1,28,00,000 | ₹8,96,000 | ₹1,28,000 | ₹10,24,000 |
| Carpet (1,200 sq ft) | ₹96,00,000 | ₹1,20,00,000 (agreement) | ₹8,40,000 | ₹1,20,000 | ₹9,60,000 |
The difference is ₹64,000. The lesson is not that one basis is better. It is that the assessed rate per square foot, not your negotiated price per square foot, sets the floor.
Example C: How loading hides in the price
| Project A (quotes on carpet) | Project B (quotes on super built-up) | |
|---|---|---|
| Quoted rate | ₹6,000 per sq ft | ₹4,800 per sq ft |
| Area quoted | 750 sq ft carpet | 1,000 sq ft super built-up |
| Price | ₹45,00,000 | ₹48,00,000 |
| Effective rate on carpet area | ₹6,000 | ₹6,400 |
Project B looks cheaper per square foot and costs more per square foot of usable space. Convert to carpet area before you compare.
7. Other Documents and Tax Savings
This is a brief outline. Separate guides cover each deed.
- Gift deed. A gift to a member of the donor's family pays 0.5% of market value as stamp duty, and any other gift pays the conveyance rate, plus a registration fee of about 1%.
- Power of attorney. A PoA to a promoter or developer carries fixed duty by value slab, from ₹5,000 up to ₹30 Lakhs to ₹75,000 above ₹3 Crore.
- Lease. The duty depends on the term and uses the conveyance rate on a multiple of the annual rent, or on market value for a lease beyond 30 years.
Section 80C. A buyer of a residential property can claim stamp duty and registration charges within the ₹1.5 Lakh overall limit in the year of payment, under the old tax regime. Income-tax law was reorganised in 2026, so confirm the section reference before filing.
8. Documents Checklist and Common Area Errors
For the SRO appointment
- Agreement for sale and draft sale deed stating the carpet area
- RERA registration details and the carpet area certificate
- Sanctioned plan and completion or occupancy papers for new flats
- e-Assessment slip and GRIPS challan
- PAN and Aadhaar of all parties; NRI documents where relevant
- Latest municipal tax receipt, mutation record and society or association NOC
- TDS proof where the consideration is ₹50 Lakhs or more (Form 26QB; confirm current references)
- Two witnesses with ID
Common errors
- Entering the super built-up figure in the carpet area box, or the reverse.
- Comparing builder quotes without converting to a common basis.
- Using area figures in the e-Requisition that differ from the agreement.
- Ignoring the higher-of rule and assuming a smaller area lowers the bill.
- Forgetting the effect of the ₹1 Crore step when an area basis pushes the value across it.
- Skipping the RERA carpet area certificate when the agreement does not state it.
- Forgetting municipal mutation after registration, which is a separate step and charge.
9. Frequently Asked Questions
Does West Bengal charge stamp duty on carpet area or super built-up area?
It is not settled in the sources we could verify. The registration department's older FAQ says super built-up area is used, some 2026 commentary says carpet area, and the portal's flat tool asks for carpet, built-up and super built-up area. Enter figures that match your agreement and RERA papers and confirm on the e-Assessment slip.
What is the difference between carpet area and super built-up area?
Carpet area is the usable floor space inside the flat. Super built-up area adds the walls, balconies and a share of common areas, so it is typically 25% to 40% larger.
Does RERA decide the stamp duty value of my flat?
No. RERA governs how a flat is quoted and sold, on carpet area. The registration department separately computes the market value used for stamp duty.
What is the stamp duty on a flat in Kolkata in 2026?
6% up to ₹1 Crore and 7% above in municipal and corporation areas, plus a registration fee of about 1%, charged on the higher of the agreement value and the assessed market value.
Will a smaller carpet area lower my stamp duty?
Only if the assessed market value is above your agreement price and the area basis reduces it. If your agreement value is already the higher figure, duty follows your agreement value.
Is the 2% rebate still available?
No. It ended on 30 June 2024.
Disclaimer: This article is for general information and is not legal or tax advice. Valuation rules, rates and portal procedures are set by the Government of West Bengal and can change. Confirm your figures on the official e-Assessment slip or with an advocate or the Registrar's office before paying.