City and town classification of constituencies and local authorities

Introduction

This page and the associated downloads describe the House of Commons Library’s city and town classification for Great Britain, which categorises areas based on the size of the settlements people live in. It is intended for analysing data and understanding differences, trends and inequalities across Great Britain. Each constituency, local authority and small area is assigned to one of six categories like “core city” or “small town”. The classification gives an alternative to rural-urban classifications for analysis.

Why cities and towns?

Classifying areas according to whether they are urban or rural is a familiar and useful concept, but this does not allow for comparing between different sizes of settlements. For example, Cardiff (population 367,000) and Attleborough (population 12,000) share the same rural-urban classification of “Urban: Nearer to a major town or city”.  So, the rural-urban classification wouldn’t be able to tell us about variation between settlements of different sizes, since it classifies both small towns and large cities with the same broad brush. 

The city-town classification is not intended as a replacement for other classifications, since for many datasets, differences between urban and rural areas are the right thing to capture. But sometimes we can gain additional insight by looking at variation between cities, towns, and villages.

Interactive map of the constituency classification

How does the classification work?

The classification categorises each built-up-area based on its population into the following categories:

• 12 core cities: major population and economic centres (for example London, Glasgow, Sheffield)
• 23 other cities: other settlements with a population of 180,000 or above (for example Leicester, Portsmouth, Aberdeen)
• 116 large towns: settlements with a population between 60,000 and 179,999 (for example Warrington, Maidstone, Barnsley)
• 271 medium towns: settlements with a population between 25,000 and 59,999 (for example Gravesend, Batley, Dunfermline)
• 787 small towns: settlements with a population between 7,500 and 24,999 (for example Heanor, Yeadon, Cinderford)
• 6,593 villages and small communities: settlements with a population under 7,500 (for example Goff’s Oak, Aylsham, Ystradgynlais)

This classification isn’t intended to resolve long-standing disputes about which settlements deserve to be called ‘cities’, ‘towns’, or ‘villages’. In fact, it takes no account of the ceremonial definition of ‘city’, using the term only as a way to identify larger settlements. For instance, St Albans is identified as a ‘large town’ here because its population is 77,000 – even though it has city status. Luton, on the other hand, doesn’t have city status, but is classified here as an ‘Other City’ because its population is 248,000.

The precise division between large, medium and small towns is, to a large extent, subjective. The distinctions used here aim to provide a useful distribution of settlements across six categories for the purposes of analysis at constituency and local authority level.

Classifying constituencies and local authorities

Each constituency and local authority is assigned to one of the above categories based on the settlement classification that the largest number of people live in. In some cases, such as constituencies in large cities like London and Birmingham, the whole constituency is in the same classification.

In other cases, a constituency can be split between multiple classifications. For example, Barnsley North is split between a large town (Barnsley) and a number of small towns and villages. 44% of the constituency’s population lives in the large town, larger than any other category, so the constituency is classified as ‘large town’.

More specifically, the analysis matches 230,000 output areas in Great Britain to built-up areas. Output areas are small geographical areas developed by the Office for National Statistics (ONS) and National Records of Scotland for census data. 2024 output area population estimates for England and Wales, and 2022 output area census population counts for Scotland, are used to calculate settlement sizes.

Output areas are matched to constituencies on a best-fit basis, and population numbers are aggregated to calculate the population in each settlement classification. Output areas which do not match to a built-up area are classified as part of the “village or smaller” category.

Wider conurbations of core cities

The classification also indicates whether a settlement is part of the wider conurbation of a core city. This refers to towns and cities which are contiguous with or fully contained by core cities – like Dudley (near the core city of Birmingham), St Helens (near Liverpool), and Staines-upon-Thames (near London).

This means that there are two versions of the classification. The summary classification categorises places like Dudley, St Helens and Staines-upon-Thames as “Core city or wider conurbation”. The specific classification categorises them based on their population size, for example large town or small town.

While the built-up area geography used in the analysis splits London into its constituent boroughs, these are all categorised as ‘core city’ in both versions of the classification.

Files available for download

On this page you can download the following data files relating to the classification:

• Settlement_class.csv: categorisation of built-up areas into the categories described above
• OA_classification.csv: categorisation of output areas into the categories described above, with geographical lookups
• Constituency_classification.csv: categorisation of parliamentary constituencies into the categories described above
• Local_authority_classification.csv: categorisation of local authorities (as of 2026) into the categories described above
• 2018_classification_archive.zip: archive of our previous version of the city and town classification from 2018. This provides data for 2011 output areas, pre-2024 constituency boundaries, and 2018 local authority boundaries, based on 2011 built-up areas/subdivisions in England and Wales and settlement geographies for Scotland.

Notes and other work

The Office for National Statistics has produced analysis of towns and cities, looking at characteristics of built-up areas in the 2021 census.

The original 2018 analysis drew on work by the Centre for Towns.

Northern Ireland is not included in this analysis because the Ordnance Survey built-up area geography covers only Great Britain.

Sources

OS and ONS Geography: Built up areas (2024), output area population-weighted centroids (2021)

National Records of Scotland: Census 2022 geographies, Census 2022 results

ONS: mid-2024 population estimates for output areas