FSI calculator for Chennai and Tamil Nadu
A residential plot in Tamil Nadu may build up to FSI 2.0, twice its area, under TNCDBR 2019, and a road 9 m or wider opens premium FSI on top. Enter the plot's size and the road it faces: you get the FSI and built-up area your plot can actually reach after its setbacks, the floors and height, and premium FSI with its charge, each with the rule it comes from.
Free, and no sign-in.
- FSI reached
- 1.705 of 2.0
- Floors
- Stilt plus 3, up to 14 m
- Setbacks
- 3 m front, 1.5 m sides and rear
Freeevery run
What we need
One thing at a time. Fill it in and press Run.
The answer
Worked out from the figures you gave, with the rule behind each number.
Nothing run yet. The answer appears here with everything this mini adds:
- Premium FSI worked out too, with what it adds and its charge as a share of the guideline value
- Every figure with its TNCDBR 2019 rule, so an architect can check it
- The same engine as Build Scope and the FSI calculator page, so the figures agree everywhere
FSI in Tamil Nadu, briefly
The floor space index is the total floor area of a building divided by the area of its plot. Tamil Nadu sets it, with the floors, height and setbacks that go with it, in the Tamil Nadu Combined Development and Building Rules, 2019.
- Base FSI
- 2.0
For a non high-rise building anywhere in the state. A high-rise building gets 2.0 on a 12 m road, 2.5 on 15 m and 3.25 on 18 m or wider.
- Premium FSI
- 30%, 40%, 50%
More floor area over the base, by road width: 9 to 12 m, 12 to 18 m, 18 m and wider (Rule 49), bought at 50% of the guideline value (40% for a high-rise).
- Small buildings
- 14 m
Up to 16 homes and 300 sq.m of shops may rise to 14 m, usually stilt plus three floors, since G.O. Ms. No. 69 of 2024.
How to calculate the FSI of a plot in Tamil Nadu
- 1
Enter the plot
The area from the patta or deed, the frontage along the road and the depth, in feet or metres. For an odd shape, the largest rectangle inside it.
- 2
Enter the road
The width of the road the plot faces today, and any depth a proposed road widening will take.
- 3
Read the figures and their rules
The FSI and built-up area the plot reaches, the floors, height and setbacks, and premium FSI, each with the TNCDBR 2019 rule it comes from.
When it helps with land
Before buying a plot
Know how much you can build before you pay for land priced on what it can carry.
Checking a builder's offer
See whether the floors and the built-up area in a joint development offer fit the rules for that road.
Briefing an architect
Start the design from the setbacks and floors the rules allow, with the rule for each.
These are the rules applied to the figures you give, not an approval. Zones such as the aquifer recharge area, a coastal zone or the Redhills catchment change the limits, so tick them if they apply, and the planning authority decides on the drawn plan.
Questions people ask
How is FSI calculated?
FSI is the total floor area of all floors divided by the plot area. With FSI 2.0, a 2,400 sq.ft plot may carry 4,800 sq.ft of floor area, though its setbacks and height limit often keep it below that, which is what this calculator works out.
What is the FSI in Chennai and Tamil Nadu?
Under TNCDBR 2019, FSI 2.0 for a non high-rise building anywhere in the state, CMDA and DTCP areas alike. A high-rise building gets 2.0 on a 12 m road, 2.5 on 15 m and 3.25 on 18 m or wider; the aquifer recharge area caps FSI at 0.8.
What is the FSI for a 30 feet road in Chennai?
A 30 ft road is about 9.1 m, so a building there is non high-rise with FSI 2.0, a 3 m front setback and up to 14 m height for a small building. Premium FSI of 30% (FSI 2.6) is open to it; whether it adds floor area depends on the plot, which the calculator shows.
What is the FSI for a 40 feet road?
A 40 ft road is about 12.2 m: FSI 2.0 for a non high-rise building, premium FSI of 40% (FSI 2.8), and a high-rise building becomes possible on a plot with room for 7 m setbacks all round.
What are premium FSI charges in Chennai?
Premium FSI is bought at 50% of the guideline value for each sq.m of extra floor area on a non high-rise building and 40% on a high-rise (Rule 49). Within 500 m of a Metro Rail corridor the charge is halved.
How many floors can I build on one ground?
On a 40 by 60 ft plot (2,400 sq.ft) facing a 30 ft road, stilt plus three floors up to 14 m, about 4,093 sq.ft of floor area. A wider road, a corner or more homes change it, so enter your own figures.
What is not counted in FSI?
Rule 29 leaves out stilt and basement parking floors, stair and lift rooms on the terrace and in parking floors, servants' toilets, and watchman and caretaker booths. Every habitable floor counts in full, balconies included.
Is this the same figure as Build Scope?
Yes. It runs the same engine as Build Scope and the FSI calculator page, so the figures agree. Build Scope adds the parking, the scenarios and a drawn plan for the plot.
Is this free?
Yes, and it needs no account.