Free tool
FAR calculator
Enter the site area, the allowed floor area ratio and ground coverage. See the most floor area you can build, the footprint, how many floors that needs and how tall it gets.
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FAR (floor area ratio, also FSI) is total floor area divided by site area. Rules differ on what counts towards it; check your local code.
Most floor area you can build (GFA)
6,755 m²
Largest footprint
1,062 m²
Floors needed on that footprint
7
Height at that floor height
22.4 m
Open ground left
869 m² · 45%
In square feet (GFA)
72,710 ft²
How to do it
- 1
Site area
Enter the area of the plot in square metres.
- 2
The rules
Enter the allowed FAR (or FSI) and ground coverage from the local code.
- 3
Floor height
Enter floor to floor height to see the building’s height.
- 4
Read the result
Maximum floor area, footprint, floors and open ground left.
What FAR means
Floor area ratio (FAR), also floor space index (FSI) or plot ratio, is the total floor area of the buildings on a plot divided by the plot area. A FAR of 2.5 on a 1,000 m² plot allows 2,500 m² of floor area, however it is stacked.
What counts towards it
Codes differ on what is counted: basements, balconies, stairs, parking and plant rooms are often in or out by rule. This calculator uses gross floor area; check what your code excludes.
Questions
How do I calculate FAR?
+
Divide the total floor area of all floors by the site area. For the reverse, multiply the site area by the allowed FAR to get the most floor area you can build.
Is FAR the same as FSI?
+
Yes. Floor space index (FSI) in India and plot ratio in the UK and Singapore mean the same: floor area over site area.
Why does coverage matter?
+
Coverage limits the footprint. With a fixed floor area, a smaller footprint means more floors and a taller building.
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