CALCULATE WITH CONFIDENCE

Real Estate & Housing · Property measurement

Open Space Ratio Calculator

Calculate open space as a share of site area and, separately, as a ratio to total counted floor area.

Real Estate & Housing

Enter your property scenario

Exact entered decimals · no live property data

Use one consistent area unit and measurement basis unless a unit selector is provided. Separate schedule rows with semicolons or new lines, and row values with commas. Your values stay in this browser.

Real-estate result

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Enter valid values to see the result.

Your entries are calculated in this browser and are not submitted to 365CALCS.COM.

Quick guide

How to use this calculator

  1. Enter amounts from the same property scenario and use consistent periods and units.
  2. Use visitor-entered rates and allowances from your own documents rather than assuming a local rule.
  3. Review the component results and the calculator-specific decision boundary before acting.

Calculation method

Calculation method

Site open-space share = open space ÷ site area; floor-area open-space ratio = open space ÷ counted floor area.

Entered fixed decimals remain exact through rational arithmetic. Planar distance outputs that require square roots use bounded numerical evaluation. Values round only for display, and unsupported or undefined states return an explicit message.

Worked example

Worked example

Six hundred open-space units on a 2,000 site with 3,000 counted floor area gives 30% of site and a 0.2 floor-area ratio.

Site open-space share = open space ÷ site area; floor-area open-space ratio = open space ÷ counted floor area.

Supported inputs

Precision and limits

International scope

No currency, market price, interest rate, tax, tenancy rule, planning code, lender policy, or measurement definition is supplied automatically.

Scenario, not a decision

Results are arithmetic scenarios from visitor-entered values—not an appraisal, loan approval, legal interpretation, planning determination, forecast, or professional recommendation.

Precision and privacy

Inputs accept bounded plain decimals and remain in this browser. The engine prevents invalid denominators and misleading non-finite results.

Calculator-specific boundary

Open space, landscaped area, communal amenity, public realm, permeability, and unbuilt site area are different concepts. Use the governing definition.

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