NYC FAR & Buildable Area Calculator
Calculate maximum buildable floor area and unused development rights from lot size and FAR.
Maximum zoning floor area — not all building space counts toward FAR (cellars, mechanical deductions, and open terraces are typically excluded; see ZR 12-10). Bonuses (inclusionary housing, plazas) can raise the effective FAR. Confirm your district's FAR and lot area on ZoLa or by looking up the property below.
Basic FAR Calculation
FAR = Maximum Allowed Floor Area / Lot Area
Or inversely: Maximum Allowed Floor Area = Lot Area x FAR
Example 1: Simple Residential
A 2,500 sq ft lot in an R6 district (FAR 2.43 for residential):
- Maximum Floor Area = 2,500 x 2.43 = 6,075 sq ft
- This could be a 3-story building with ~2,025 sq ft per floor
- Or a 4-story building with ~1,519 sq ft per floor
Example 2: Commercial Mixed-Use
A 10,000 sq ft lot in a C4-6 district (FAR 10.0 commercial, 10.0 residential):
- Maximum Floor Area = 10,000 x 10.0 = 100,000 sq ft
- With inclusionary housing bonus: up to 12.0 FAR = 120,000 sq ft
- Could be a 20-story mixed-use building
What Counts as Zoning Floor Area
Not all building space counts toward FAR. The Zoning Resolution (ZR 12-10) defines "floor area" as the sum of gross areas of all floors, with specific exclusions:
- Included: All habitable floor area, enclosed parking above grade, mechanical space above allowable deductions
- Excluded: Cellars (if less than 50% above curb level), up to 200 sq ft of mechanical per dwelling unit, open balconies, terraces, outdoor recreation space
FAR by Common Zoning Districts
- R1/R2: 0.5 FAR (single-family detached)
- R3-R5: 0.5-1.25 FAR (low-density residential)
- R6-R7: 0.78-4.0 FAR (medium-density residential)
- R8-R10: 4.0-10.0 FAR (high-density residential)
- C1-C4: 1.0-10.0 FAR (commercial, varies widely)
- C5-C6: 4.0-15.0 FAR (high-density commercial)
- M1-M3: 1.0-10.0 FAR (manufacturing)
Unused FAR (Development Rights)
If your building uses less FAR than allowed, the difference is unused development rights (commonly called "air rights"). These rights have monetary value and can potentially be transferred to adjacent lots through zoning lot mergers.
Calculating Unused FAR
Unused FAR = Allowed FAR - Built FAR
Example: 5,000 sq ft lot in R7A (FAR 4.0). Building has 12,000 sq ft of floor area.
- Allowed: 5,000 x 4.0 = 20,000 sq ft
- Built: 12,000 sq ft
- Unused: 8,000 sq ft of development rights
Frequently Asked Questions
How do I calculate FAR for my NYC property?
FAR = Maximum Floor Area / Lot Area. Find your zoning district on ZoLa, look up the permitted FAR, and multiply by your lot area. The result is the maximum building floor area allowed.
What is the highest FAR in NYC?
The highest FAR in NYC is 18.0, in the R12 high-density residential district created by the 2024 City of Yes rezoning. Among commercial districts, C5/C6 districts in Midtown reach a base FAR of 15.0, and bonuses can push effective FAR higher.