What Is Floor Area Ratio (FAR)? A Complete Guide With Examples
Data version: Q2 2026 · Last updated 2026-05-13
TL;DR. Floor Area Ratio (FAR) is the single most important number on your zoning report. Here is what it means, how to calculate it, and how it controls what you can build — with worked examples.
Summary
Floor Area Ratio (FAR) is total building floor area divided by lot area, measured as a unitless ratio. A FAR of 0.5 on a 10,000 sqft lot allows up to 5,000 sqft of total building floor area. FAR is the primary number that controls maximum building size in most U.S. zoning codes and is the most cited figure in financial pro formas because lenders underwrite to gross buildable square footage. Typical FAR ranges by zone: rural/agricultural 0.05-0.15, single-family residential 0.3-0.6, two-family/townhouse 0.5-1.5, multi-family low-rise 1.0-3.0, neighborhood commercial 0.5-2.0, general commercial/mixed-use 2.0-5.0, downtown/dense commercial 5.0-15.0, Manhattan high-density commercial 10.0-18.0. FAR binds independently from height and lot coverage; the buildable size is the intersection of all three. Most cities offer FAR bonuses (typically 25-50% above base) for affordable housing, transit-oriented development, public open space, or historic preservation. What counts toward FAR varies by city — common exclusions include open balconies, mechanical rooms, and below-grade basements.
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