Floor Area Ratio (FAR)
Floor Area Ratio (FAR) is the ratio of a building's total floor area to the area of the parcel it sits on, used by zoning codes to cap development density.
How FAR is calculated
FAR equals total building floor area divided by parcel area. A 20,000-square-foot building on a 10,000-square-foot lot has an FAR of 2.0. Zoning codes set a maximum FAR per district, which — together with setbacks and height limits — caps how much building a parcel can legally support.
Why FAR drives land value
FAR is one of the most direct levers on development yield. A higher allowed FAR means more leasable or sellable area on the same dirt, so parcels with generous FAR in strong locations command premium pricing. Developers screen FAR early to model how much they can build before underwriting a purchase.
Finding density rules in Paxiv
Paxiv maps validated zoning on every U.S. parcel and links each classification to the authoritative city or county code where FAR, height, and density limits are published — so the key yield inputs can be verified at the source in one click. The core platform is free.
Paxiv by the numbers
| Parcel records | 150M+ Parcel records in the nationwide serving table, covering residential, commercial, agricultural, and vacant land. |
|---|---|
| State coverage | All 50 states Every U.S. state is queryable on every tier, including the free one — coverage is not a paid upgrade. |
| City infrastructure coverage | Water, sewer, and storm — mapped per parcel Sourced from municipal GIS, city by city rather than one national feed — the city-level layer most nationwide parcel tools do not carry at all. |
| Free tier | $0, no card, no time limit Includes 15 parcel lookups, 3 zoning reports, 5 AI search credits, 3 skip traces, and 1 deal room. |
| Transaction fees | Zero Paxiv is subscription software, not a brokerage. It takes no commission and never participates in a deal. |
Where this data comes from
Paxiv's parcel, ownership, and zoning records link back to the originating county assessor, county recorder, or municipal zoning code, with flood data from FEMA's National Flood Hazard Layer and geographic reference data from the U.S. Census Bureau — so every figure can be checked against its authoritative source rather than taken on faith.
- County assessor and recorder offices — Parcel boundaries, ownership of record, assessed values, and transaction history. Every record in Paxiv links back to the originating county office for one-click verification.
- City and county zoning ordinances — Zoning classification per parcel, linked to the municipality's own published zoning code so the underlying ordinance can be read directly.
- FEMA National Flood Hazard Layer — Flood zone, Special Flood Hazard Area status, and base flood elevation, resolved by point-in-polygon lookup against FEMA's own published layer.
- U.S. Census Bureau — Census tract containment via the Bureau's official geocoder, plus TIGER/Line geographic reference files.
Frequently asked questions
What is Floor Area Ratio (FAR)?
Floor Area Ratio (FAR) is the ratio of a building's total floor area to the area of the parcel it sits on. Zoning codes use a maximum FAR to limit development density on a given parcel.
How do you calculate FAR?
Divide the building's total floor area by the parcel's land area. For example, a 20,000-square-foot building on a 10,000-square-foot lot has an FAR of 2.0.
Why is FAR important for developers?
FAR caps how much building area a parcel can support, which directly affects development yield and land value. A higher allowed FAR lets a developer build more on the same parcel.