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Calcimator

Buildable Area Calculator

Calculate maximum buildable area from FAR, lot coverage, setbacks, and height limits.

Inputs

SF
ft
ft
%
ft
ft
ft

Results

Max Buildable Area

40,000 SF

Max Footprint

12,000 SF

Max GFA (FAR Limit)40,000 SF
Buildable Envelope13,200 SF
Setback Area6,800 SF
Effective FAR2
Effective Coverage60%
How to Use This Calculator
  1. Enter Lot Area in square feet, Lot Width, and Lot Depth from the survey or property record.
  2. Set Floor Area Ratio (FAR) and Max Lot Coverage % from the applicable zoning code.
  3. Enter Front, Side, and Rear Setback distances to calculate the net buildable footprint.
  4. Set Max Stories allowed by zoning.
  5. Review Max Buildable Area (FAR-limited) and Max Footprint (coverage-limited) — the binding constraint is the smaller value.
  6. Use outputs to assess development feasibility before ordering full engineering or purchasing the site.

What each input means

Lot Area
Total lot area in square feet.
Lot Width
Lot width (frontage) in feet.
Lot Depth
Lot depth in feet.
Floor Area Ratio (FAR)
Maximum floor area ratio from zoning code.
Max Lot Coverage
Maximum percentage of lot that can be covered by building.
Front Setback
Required front setback distance.
Side Setback
Required side setback distance (each side).
Rear Setback
Required rear setback distance.
Max Stories
Maximum number of stories allowed.

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Lot Area = 20000, Lot Width = 100, Lot Depth = 200, Floor Area Ratio (FAR) = 2 = 9 input(s) provided
  2. Calculate Max Buildable Area
    Max Buildable Area
    40000 = 40000
  3. Calculate Max Footprint
    Max Footprint
    12000 = 12000
  4. Calculate Max GFA
    Max GFA
    40000 = 40000
  5. Calculate Buildable Envelope
    Buildable Envelope
    13200 = 13200

Engine last updated . Checked against 2 independently-derived tests how we verify calculators.

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