Floor area ratio (FAR) is a building's total floor area divided by the area of its lot, and zoning codes cap it to limit how much can be built on a site. A GIS or zoning lookup tool gives the number for a parcel; to see whether FAR, height or parking is the real limit and what the result is worth, a feasibility model is the tool, and that is where Titleman fits.
Updated 19 October 2026. Published by Titleman, which makes one of the tools compared.
The formula
FAR = gross floor area ÷ lot area, so maximum floor area = lot area × allowed FAR.
For example, an illustrative 20,000 sf lot zoned at FAR 3.0 allows up to 60,000 sf of floor area.
Why FAR is often not the binding limit
Same lot, other rules:
| Rule | Example limit | What it allows |
|---|---|---|
| FAR | 3.0 | 60,000 sf |
| Lot coverage and height | 60% coverage, 4 stories | 12,000 × 4 = 48,000 sf |
| Parking | 1 space per unit, surface only, 30 spaces fit | about 30 units |
The smallest number wins: height and coverage cap the building at 48,000 sf, not 60,000.
From floor area to units: for example, 48,000 sf at 82 percent efficiency is about 39,400 sf of rentable area; at an average of 850 sf a unit, that is about 46 units, before parking. With only 30 spaces, parking decides.
How a team gets to that answer today
Find the district on the zoning map, read the code for FAR, height, setbacks, coverage, parking and floor area definitions, check overlays and bonuses, sketch a massing, then build a cost and return model. Reading the code is where most hours and most mistakes go.
Tools for each step
| Option | Best for | What it does | Where it stops | Pricing model |
|---|---|---|---|---|
| GIS or zoning lookup tool | A quick district and FAR for a parcel | Map layers and code summaries | No program, cost or return | Subscription or free map |
| Architect test fit | Final massing before design | Drawn options under all rules | Days, a fee per site | Fee per study |
| Spreadsheet | Floor area and unit math | Your formulas | Code reading done by hand | Staff time |
| ChatGPT-style general assistant | Explaining a code section you paste in | Plain-language summary | Can misread or miss an overlay | Per-seat subscription |
| Titleman | The limit and the return together | District, FAR, height, maximum buildable area with sources; ranked schemes in a live Excel | Not a stamped zoning opinion or a test fit | Credits per run; ask on a demo |
Where Titleman fits
From an address or APN, a Titleman feasibility run reads the zoning and returns the district, FAR, height and maximum buildable area, each with its source, then runs every lawful use, class and unit size and keeps up to 10 schemes ranked by return. The median run took about 28 minutes on production runs in the 30 days to 18 October 2026. Where a rule could not be found, the gap is named. For a binding answer on an unclear code section, a zoning attorney or the planning office is still the right call.
FAQ
How do you calculate FAR?
Divide gross floor area by lot area. For example, 60,000 sf on a 20,000 sf lot is a FAR of 3.0.
Does FAR tell me how tall a building can be?
Not directly. The same FAR can be a low building covering the lot or a tall one on part of it. Height, setbacks and coverage set the shape and can cap floor area below FAR.
What counts as floor area?
It depends on the code. Many exclude some parking, mechanical space or below-grade floors, so read the definitions section that governs the parcel.
Can a site exceed its FAR?
Sometimes, through a density bonus, a transfer of development rights, a variance or a rezoning. Each needs an approval, with time and risk.
The next step after FAR: how many units can be built on a parcel. Also: development feasibility and residual land value with AI and parcel data and a zoning check before underwriting. Compare lookup tools: zoning lookup tools by address. To check a parcel, request a demo.