Floor area ratio, coverage and setbacks

m
m
Floor-area ratio allowed by zoning.
%
Maximum footprint as a % of the plot.
Setbacks
m
m
m

Results

Max buildable floor area
--
Plot area × FAR
Plot area --
Max footprint (coverage) --
Footprint after setbacks --
Governing footprint --
Estimated achievable floors --

Plot top view

Plot Setback zone Buildable footprint

Feasibility estimate only — local planning rules and zoning bylaws always prevail.


About FAR & Buildable Area

The FAR calculator turns zoning numbers into buildable reality. Enter your plot dimensions, the floor area ratio allowed by zoning, the maximum site coverage, and the required front, rear, and side setbacks — and it computes the maximum buildable floor area, the footprint each rule permits, and which constraint actually governs.

Floor area ratio is the total floor area you may build divided by the plot area: a 600 m² plot with a FAR of 1.5 allows 900 m² of gross floor area. But the footprint is capped twice — by the coverage percentage and by whatever rectangle survives after the setbacks — and the calculator compares both, tells you which one governs, and estimates how many floors you would need to use the full FAR.

A top-view diagram shades the setback zone and the buildable footprint so you can see the constraint at a glance. Developers, architects, and lot buyers use it for quick “what can I build here” feasibility checks — free, in the browser. Local planning rules and zoning bylaws always prevail over this estimate.

How to use FAR & Buildable Area

  1. Enter the plot width and depth — the plot area is computed for you.
  2. Set the FAR coefficient allowed by your zoning.
  3. Enter the maximum site coverage percentage and the front, rear, and side setbacks.
  4. Read the maximum buildable floor area, the governing footprint, and the estimated number of floors.
  5. Check the top-view diagram to see the setback zone and buildable area.

Frequently asked questions

The ratio of total gross floor area to plot area. FAR 2.0 on a 500 m² plot allows 1,000 m² of floor area, stacked however the other rules permit — two full-footprint floors, four half-footprint floors, and so on.

FAR limits the total floor area across all levels; coverage limits the ground footprint as a percentage of the plot. A project can be well under its FAR yet blocked by coverage, or vice versa — the calculator shows which limit binds.

Setbacks shrink the buildable rectangle: the usable width is the plot width minus both side setbacks, and the usable depth loses the front and rear setbacks. If that footprint is smaller than the coverage allowance, the setbacks govern.

By dividing the maximum floor area by the governing footprint. If zoning allows 900 m² and the footprint is 300 m², you would need about three floors to use the full FAR — subject to any height limit in your zone.

No — it is a feasibility estimate. Real zoning includes height limits, parking minimums, exemptions from the FAR count, and daylight rules the tool does not model. Confirm everything with your local planning authority before committing to a design.

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