FSI Calculator
Calculate maximum buildable area and approximate achievable floors from plot area and FSI.
About this calculator
Two developers can look at the same plot area and permissible FSI and picture very different buildings, because FSI alone gives you total buildable area, not the number of floors, and translating one into the other requires also knowing how much of the ground footprint each floor will actually occupy. This calculator multiplies plot area by permissible FSI to find maximum total buildable area, then divides that by the product of plot area and a ground coverage percentage to approximate how many floors of that footprint size the total area could support. Enter plot area, FSI and your planned ground coverage, and see both the buildable area ceiling and a realistic floor count instead of estimating floors by guesswork. This is the Indian regulatory term for the same concept called FAR (Floor Area Ratio) elsewhere, and the floor estimate is approximate, actual floor count also depends on setbacks, height restrictions and structural design, so confirm against your local development authority's specific rules.
Worked example
3,000 sqft plot, FSI 2, 40% ground coverage
Result: Max buildable area = 6,000 sqft, ~5 floors
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