Output Area Sizes

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What are Output Area Sizes?

Output Areas (OAs) and Postcodes are key tools for capturing and analysing statistical data and grouping addresses. While postcodes serve various general purposes, most geographic areas like OAs are specifically designed for the census. These areas are crucial for organising population and other statistics into comparable units, aiding planners and policymakers in resource allocation and decision-making.

Geographic Areas and Census Geography

The hierarchy of geographic areas used in census geography includes:

  • Output Areas (OAs): The smallest census unit, designed for detailed population and statistical data.
  • Lower Super Output Areas (LSOAs): Larger areas that group multiple OAs.
  • Middle Super Output Areas (MSOAs): Broader regions that encompass multiple LSOAs.

These nested structures allow for scalable data analysis, with each MSOA containing LSOAs and each LSOA containing OAs. This layered approach is widely used for releasing datasets even after the census, making these areas essential for data modelling and grouping purposes.

Suppression of Unlinked OAs

To ensure accurate and meaningful analysis, any OAs that do not link to a postcode have been suppressed. There are approximately 200 unlinked OAs across the UK.

Postcodes for Marketing and Analysis

Postcodes vary significantly in size and use:

  • A postcode can represent as few as one address or as many as 100.
  • This variability makes postcodes more suited for marketing and address-based analysis, providing an effective way to associate an address with a specific location for comparison or modelling.

By combining the precision of OAs and the flexibility of postcodes, analysts can perform granular location-based studies and develop targeted insights for planning, marketing, and resource distribution.

Output Area Size (OA)Lower Super Output Area Size (LOSA)Middle Super Output Area Size (MSOA)
Min Population1001,0005,000
Max Population6253,00015,000
Min Household404002,000
Max Household2501,2006,000
Number in England171,37232,8446,791
Number in Wales10,0361,909410
Number in Scotland42,6046,9761,279
Number in NI5,022890n/a
Note: In Scotland, the equivalent to LSOAs are referred to as Datazones and MSOA as Intermediate Zones. In Northern Ireland LSOAs are referred to as SOAs.

For more detailed insights into Output Areas, explore our Geodemographic data product which provides extensive Geodemographic Data covering the whole of the UK.

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