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Site Coverage Calculator

Use this site coverage calculator entirely in your browser.

ResultPlanned site coverage: 30.00%

Combined footprint: 240.00 m²

User-entered 35.00% limit: 280.00 m²

40.00 m² below the entered planning limit.

This comparison uses only the limit you entered and does not determine zoning or permit compliance.

Calculations happen locally in your browser.

How to use this calculator

  1. Enter the labelled values and review the live result.
  2. Review the live result and use Copy result when you need to share it.

How the calculation works

Existing and proposed ground footprints are added and divided by total lot area; the result is compared only with the user-entered planning limit.

Formula

Coverage percentage = (existing footprint + proposed footprint) ÷ lot area × 100

Step-by-step calculation

  1. Enter the labelled values and review the live result.
  2. Existing and proposed ground footprints are added and divided by total lot area; the result is compared only with the user-entered planning limit.
  3. Check the displayed result, then copy it if needed.

Worked example

A 180 m² building plus a 60 m² addition on an 800 m² lot gives 30% site coverage.

Risk guidance

What site coverage measures

This tool adds the existing and proposed ground-level building footprints and divides that total by the lot area. Planning schemes may define site area, building coverage, projections, parking structures, and exclusions differently.

Enter a limit from an authoritative source

The calculator does not look up zoning. Enter only a coverage limit verified for the property, planning zone, overlays, building type, and current rules. A result below that number is not approval and does not test other controls.

Other planning controls still apply

Setbacks, height, floor-area ratio, open space, permeability, parking, access, heritage, environmental, fire, utility, and easement requirements may independently affect a proposal.

Frequently asked questions

Does the calculator know my zoning limit?

No. You enter the limit. Confirm it using current official property and planning information before using the comparison.

Does a result below the entered limit mean the project is permitted?

No. Coverage is only one possible planning control, definitions vary, and permits or professional review may still be required.

Does this tool send my inputs anywhere?

No. The interactive calculation runs in your browser and this site does not submit tool inputs to a backend.

How should I use the result?

Use it for early planning only. Verify measurements, definitions, current local requirements, and the complete design with the relevant authority and appropriately qualified professionals.

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