NYC zoning FAR calculator
Pick a zoning district and enter a lot area. You get the maximum floor area for each use, the City of Yes and MIH bonus figures where they apply, the height limits and lot coverage, each with its Zoning Resolution section.
Up to 15,000 sf of residential floor area
District maximums on a 5,000 sf lot. The real figure is the lower of this and what the height, setback and yard envelope can physically hold.
| Use | FAR | Max floor area | ZR |
|---|---|---|---|
| Residential | 3 | 15,000 sf | §23-22 |
| Residential with City of Yes UAPAs of right, where the floor area above the base is permanently affordable housing. | 3.9 | 19,500 sf | §27-16 |
| Residential where MIH is mappedOnly on lots inside a mapped Mandatory Inclusionary Housing area. | 3.9 | 19,500 sf | §27-131 |
| Commercial inside a C1/C2 overlayOnly where a commercial overlay is mapped on the lot. | 2 | 10,000 sf | §33-121 |
| Community facility | 3 | 15,000 sf | §23-22 |
- Street wall base: 40 to 65 ft
- Maximum height: 75 ft
- Setback above the base: 10 ft
- Maximum height with UAP: 95 ft
- Lot coverage (interior): 80%, a footprint of 4,000 sf
- Rear yard: 20 ft
- Units: at most 22 at a 680 sf dwelling unit factor (ZR 23-52)
At 80% coverage, 3 FAR needs at least 4 stories built to the full footprint, all under the 75 ft height limit. Setbacks above the base, the rear yard, courts, an irregular or shallow lot and the core all take floor plate away, so on many lots the floor area the envelope can hold is below lot area × FAR. Only a model of the actual lot shows which rule binds first.
- §23-22 · R6A bulk regulations
- §23-52 · Dwelling unit factor: 680 square feet
- §23-12 · Minimum lot area: 2375 sq. ft
- §23-12 · Minimum lot width: 25 ft
- §23-344 · Rear yard beyond 100 ft of a street: 0 ft
Figures come from the same rule corpus the RunEnvelope engine runs on, published district by district on the zoning districts reference. They are district maximums: special districts, overlays, split zoning, landmarks and the lot's own geometry are not applied here.
How the FAR math works
Floor area ratio is the total zoning floor area a building may contain divided by the area of its lot. The calculation is one multiplication: lot area × FAR = maximum zoning floor area. Each use has its own FAR, and a mixed building may use more than one, subject to the district's rules on how they combine.
R6A allows a residential FAR of 3, so 5,000 × 3 = 15,000 sf of zoning floor area. With the City of Yes Universal Affordability Preference the FAR rises to 3.9, or 19,500 sf, where the extra floor area is permanently affordable. Lot coverage on an interior lot is 80%, a 4,000 sf footprint, so the base floor area needs at least 4 full floors under a 75 ft height limit. At a 680 sf dwelling unit factor that is at most 22 units.
Three things then decide whether you can actually use it. The envelope: base height, maximum height, setbacks and the sky exposure plane in non-contextual districts. The footprint: lot coverage, rear yards and courts. The lot: a narrow, shallow or irregular parcel loses more floor plate to each of those than a regular one. That is why the calculator shows the minimum number of full floors the floor area needs next to the height limit.
What a district table cannot tell you
- ■Whether the lot sits in a special district that overrides the base FAR or height.
- ■Whether a commercial overlay or an MIH area is actually mapped on the lot.
- ■How the rules split when a lot straddles two districts.
- ■How the yards fall on each edge of an irregular or through lot, and what that does to the floor plate.
- ■What is already built on the lot, and what the unused floor area is worth to a neighbor as air rights.
The free check on RunEnvelope reads all of that for a specific address. Read how much can I build on my NYC lot for the full method, worked through on three real sample reports, or the buildable square footage guide.
Now run an actual lot.
Enter an address or BBL. We look up its lot area, district and street, then the free check shows what its envelope really holds. You can also send the lot back into this calculator.
FAR questions, answered
How do you calculate FAR for a NYC lot?
Maximum zoning floor area is lot area multiplied by the district's floor area ratio for the use you plan. Residential, commercial, community facility and manufacturing uses each have their own FAR, and some districts set a different residential FAR on wide and narrow streets. Bonuses such as the City of Yes Universal Affordability Preference or Mandatory Inclusionary Housing raise it where the lot qualifies.
What is the difference between a wide and a narrow street?
In the Zoning Resolution a wide street is 75 feet or more across; anything narrower is a narrow street. In some districts it changes the FAR itself (R6 allows 3 on a wide street and 2.2 on a narrow one), and in contextual districts it changes setbacks and height.
What FAR applies to residential use in a commercial district?
Residential use in a commercial district follows the bulk rules of its residential equivalent district (ZR 34-112). For example, residential floor area in C4-4A follows R7A. The calculator applies that equivalence automatically and says which district it used.
Why is the buildable floor area on my lot lower than lot area × FAR?
Because the floor area also has to fit inside the physical envelope: height limits, setbacks above the street wall, rear yards, lot coverage, courts and the shape of the lot. On narrow, shallow or irregular lots the envelope often binds before the FAR does. A full model of the actual lot is the only way to know.
Does this calculator replace a zoning study?
No. It shows the district maximums from the Zoning Resolution. It does not read the lot's shape, overlays, special districts, split zoning, landmarks or existing buildings. The free check on RunEnvelope does that for a specific address, and a full report models every scenario as a building.