Floor space ratio calculator for NSW

Free. The optional address lookup uses NSW Government planning data. Worked example

    The lot, or contiguous lots the development sits on, after the clause 4.5 exclusions.

    From the LEP's Floor Space Ratio Map. Write 0.5 for 0.5:1. Leave blank to find the ratio a design achieves.

    All existing and proposed buildings within the site, measured under the Dictionary definition. Leave blank to find the maximum only.

    Result

    Enter a site area, then a permitted ratio, a gross floor area, or both. The result and its working appear here as you type.

    Show working

    Each step names the rule it follows so the table can sit in a file note or Statement of Environmental Effects.

    The step table appears once there is a result.

    Arithmetic only. Confirm the mapped ratio, site area and each gross floor area classification against the applicable LEP.

    The calculator uses your figures. The address lookup reads the mapped ratio and lot areas from NSW Government planning data as a starting point; it does not confirm a site area or classify a room. A council LEP, incentive clause or SEPP can change the standard, so check the LEP and DCP that apply to the land. Meeting the ratio does not establish permissibility or compliance with height, setback, heritage, flood or other controls. Calculations run in your browser. Address searches go through Plynth to NSW planning services, and lookup responses can be cached. A share link includes your figures and schedule labels in its address.

    What is floor space ratio?

    Floor space ratio (FSR) is the gross floor area of all buildings on a site divided by the site area. It is the NSW development standard that caps how much floor space a site can hold: a ratio of 0.5:1 allows 0.5 m² of gross floor area for every square metre of site, so a 600 m² site allows 300 m². Outside NSW the same control is usually called floor area ratio or plot ratio.

    The ratio counts floor area, not footprint, so height, setbacks and site coverage are separate controls. Clause 4.4 of the Standard Instrument LEP sets out a mapped maximum, and clause 4.5 defines the ratio and site area. Check the LEP for the land and any local provisions.

    How to calculate floor space ratio

    floor space ratio = gross floor area ÷ site area

    1. 1

      Read the mapped ratio

      Find the Floor Space Ratio Map value for the land in the applicable LEP, then read clause 4.4 and any local clause that adjusts it.

    2. 2

      Determine the site area

      Take the lot, or the contiguous lots the development sits on, and remove the land that clause 4.5(4) excludes.

    3. 3

      Total the gross floor area

      Measure every floor of every existing and proposed building at 1.4 m above the floor and apply the Dictionary's inclusions and exclusions.

    4. 4

      Divide, then compare

      Gross floor area ÷ site area is the ratio achieved. Site area × permitted ratio is the maximum, and the difference is the floor area remaining or over.

    Follow the worked example for a step-by-step calculation on assumed figures.

    How site area is determined (clause 4.5)

    Clause 4.5(3)
    The site area is the lot the development is on. When the development spans two or more lots, count each lot that shares a common boundary with another lot in the development.
    Clause 4.5(4)
    Exclude land on which the proposed development is prohibited under the LEP or another law, and exclude community land or a public place except as provided by clause 4.5(7).
    Clause 4.5(5)
    In a strata subdivision, a lot stacked wholly or partly on top of another counts only where it does not overlap a lot already included.
    Clause 4.5(6)
    Do not add a lot to the site area unless the proposal includes significant development on that lot.
    Clause 4.5(7)
    For development on, above or below community land or a public place, include only the area that the development occupies or physically affects, and exclude the rest of the development land.
    Clause 4.5(8)
    Gross floor area includes every existing and proposed building within the vertical projection of the site boundaries, whether or not the proposal touches all of them.
    Clause 4.5(9)–(10)
    A consent can require a covenant that stops floor area being created on a lot that was counted to justify floor area elsewhere, and that covenant reduces the maximum on a later consolidated site.

    What counts as gross floor area

    Measured from the internal face of the external walls, or the walls shared with another building, at 1.4 m above the floor.

    Included

    • Floor area within the external wallsMeasured from the internal face of external walls (or walls shared with another building) at 1.4 m above the floor.
    • Mezzanine (a)The area of a mezzanine is included.
    • Habitable rooms in a basement or attic (b)Bedrooms, living rooms and other habitable rooms below ground or in the roof are included.
    • Shop, auditorium, cinema or the like in a basement or attic (c)Trading or assembly floor space below ground or in the roof is included.

    Excluded

    • Common vertical circulation (lifts and stairs) (d)Shared lifts and stair shafts are excluded.
    • Basement storage, vehicle access, loading, garbage and services (e)Basement storage and basement vehicular access, loading areas, garbage and services are excluded.
    • Plant rooms, lift towers and mechanical services (f)Areas used exclusively for mechanical services or ducting are excluded.
    • Car parking required by the consent authority (g)Parking that meets the consent authority's requirements, including access to it, is excluded. Parking above that requirement counts.
    • Loading and unloading space (h)Space used for loading or unloading goods, including access to it, is excluded.
    • Terrace or balcony with outer walls under 1.4 m (i)Open terraces and balconies with low outer walls are excluded. Enclosed balconies with taller walls count.
    • Void above a floor (j)Voids above a floor at the level of a storey or storey above are excluded.

    Frequently asked questions

    What is floor space ratio?

    Floor space ratio is the ratio of the gross floor area of all buildings within a site to the site area. It is the NSW planning control that limits how much floor space a site can hold, expressed as a figure such as 0.5:1 or 2:1. The same idea is called floor area ratio or plot ratio in other jurisdictions.

    How is floor space ratio calculated in NSW?

    Divide the gross floor area of all buildings within the site by the site area. A 300 m² gross floor area on a 600 m² site is a floor space ratio of 0.5:1. Clause 4.5(2) of the Standard Instrument LEP sets that definition, and the site area and gross floor area each have their own rules.

    How do I find the permitted FSR for my site?

    Search the address in this calculator: it reads the mapped ratio for the property from the NSW Planning Portal's Floor Space Ratio layer, names the LEP and clause, and fills the ratio for you to confirm. Otherwise read the Floor Space Ratio Map in the LEP that applies to the land through the NSW Planning Portal Spatial Viewer. Either way, read the written clause 4.4 and any local clause that adjusts the map. Some sites carry more than one ratio, and some LEPs set the maximum by a formula, a schedule or an incentive provision rather than the map alone.

    Does a garage or basement car park count as gross floor area?

    Car parking that meets the consent authority's requirements, including access to it, is excluded under paragraph (g) of the definition, and basement vehicular access, loading, garbage and services areas are excluded under paragraph (e). Parking above the required number of spaces is not excluded by those paragraphs, so check the DCP rate before you exclude it.

    Do balconies and terraces count?

    Terraces and balconies with outer walls less than 1.4 m high are excluded under paragraph (i). An enclosed balcony or a terrace with a taller wall is measured like any other floor area.

    Are existing buildings included in the calculation?

    Yes. Clause 4.5(8) includes the gross floor area of any existing or proposed building within the vertical projection of the site boundaries, even when the proposal does not change every building. Add retained buildings to the schedule.

    What if my design is over the permitted FSR?

    The calculator reports the excess in square metres and as a share of the control. Clause 4.6 lets a consent authority grant consent to development that contravenes a development standard such as FSR when it is satisfied the applicant has demonstrated the matters in clause 4.6(3), unless the standard is excluded from that clause. That written request is a planning judgement this tool does not make.

    Is this calculator a planning assessment?

    No. It does the arithmetic on figures you enter and shows the rules behind each step. The address lookup reads the mapped ratio and lot areas from NSW Government planning data as a starting point; it does not confirm a site area, classify a room, or apply council-specific variations, incentives or SEPP provisions. Check the applicable LEP and DCP, and use survey drawings for a real site.

    Where does the address lookup get its data?

    NSW Government services supply the data. The NSW Planning Portal finds the property and returns the mapped floor space ratio, zone and height of buildings. The NSW cadastre supplies lot areas. Address searches go through Plynth to NSW planning services, and lookup responses can be cached. Contains NSW Government data, CC BY 4.0.

    Sources

    Standard Instrument (Local Environmental Plans) Order 2006, current version for 1 July 2026 to date. Read on the NSW legislation website on 8 November 2026. Check the LEP and any local provisions that apply to the land.

    Address lookup data

    Contains NSW Government data from the NSW Planning Portal and NSW Spatial Services, CC BY 4.0. Address searches go through Plynth to NSW planning services, and lookup responses can be cached.

    Continue your site research.

    Explore planning controls for the site, including zoning, floor space ratio and mapped constraints.

    See planning due diligence in Plynth How to read zoning, height and FSR maps