Architecture
Floor Area Ratio (FAR) Calculator
The zoning rule that controls how big you can build. Plug in lot size and the FAR limit — get max allowed GFA and whether your design fits.
FAQ
What counts toward FAR? +
Conditioned interior floor area, usually measured to the outside face of exterior walls. Most codes exclude basements (if below grade by a certain amount), parking garages, mechanical penthouses, and unenclosed porches. Check your local zoning.
Typical FAR values? +
Single-family residential: 0.3 to 0.6. Multifamily: 1.0 to 3.0. Urban mixed-use: 3.0 to 10+. Downtown high-rise: 10 to 25+. Always confirm with your municipality.
FAR vs lot coverage? +
FAR controls total floor area (you can build taller with same footprint). Lot coverage controls only the footprint. Most zones use both.
FAR bonuses? +
Many jurisdictions offer density bonuses for affordable housing, open space dedication, or green building. Bonus can add 20-100% to base FAR.