Free tool
FSI / FAR buildable area calculator
See how much you can build on a plot from the floor area ratio and ground coverage allowed in your zone.
How it works
Buildable area is your plot area multiplied by the floor area ratio (FAR or FSI) allowed for your plot. Ground coverage limits the footprint per floor. FAR depends on zone and road width, so confirm the limits with a licensed architect or the local bye-laws.
What FAR actually means
Floor Area Ratio, also written FSI, is the ratio of your total built area across all floors to your plot area. At a FAR of 1.75 on a 2,400 sq ft plot you may build about 4,200 sq ft in total, however you distribute it between floors. It is the single most important number for how much house you get, and it is the one people most often assume has changed when it has not.
Three limits apply at once
This is where most plans come unstuck. FAR, ground coverage and setbacks are three separate constraints and you must satisfy all of them simultaneously, not pick the most generous.
| Limit | What it controls | Effect on a 2,400 sq ft plot |
|---|---|---|
| FAR / FSI | Total built area across all floors | At 1.75, about 4,200 sq ft in total |
| Ground coverage | How much of the plot the building may cover | At 60 percent, a footprint of about 1,440 sq ft |
| Setbacks | The open space you must leave on each side | Reduces the footprint further, and fixes its shape |
Divide the FAR by the coverage and you get roughly the number of floors your allowance implies: 1.75 divided by 0.60 is about 2.9, so around three floors. If your permitted height will not accommodate three floors, height becomes the binding limit instead and part of your FAR goes unused.
FAR did not change in 2026
This is worth stating plainly because it is widely misreported. The Greater Bengaluru (Amendment) Regulations 2026 raised residential height to 15 m, excluded up to 3 m of stilt from the height calculation, reduced setbacks and allowed more dwelling units on small plots. FAR stayed at 1.75. So the 2026 changes help you use your allowance more comfortably; they do not give you more total floor area. See what the 2026 rules changed.
Frequently asked questions
Is FSI the same as FAR?
In everyday Indian usage, yes, and they are used interchangeably in Bangalore. Both express built area as a multiple of plot area.
Does a stilt or basement count towards FAR?
Treatment differs by use and by regulation, and parking areas are often treated differently from habitable space. Since 2026 a stilt of up to 3 m is excluded from the height calculation, which is a separate question from FAR. Confirm both with your architect for your specific plot rather than assuming.
Does FAR vary by location?
It can vary by zone and by the width of the road your plot faces, and it differs outside the Greater Bengaluru Area where a planning authority may apply its own regulations. Enter the figure that applies to your plot rather than relying on the default.