This page provides constituency-level data on electorates in the UK. It includes data for both the parliamentary and the local government franchise. Not all data is available for all constituencies.

On average, there were 71,631 people registered to vote in parliamentary elections in UK constituencies in December 2021. However, this figure hides big differences between constituencies. The smallest constituency, Na h-Eileanan An Iar, had 21,304 voters, while the biggest, Isle of Wight, had 109,246. Constituency boundaries are reviewed periodically to reduce such differences. For more information, see our briefing paper on Constituency boundaries and the number of MPs.

The number of people on the electoral registers varies year by year as people move, die and come of age. Commentators have also warned that the number of people on the registers reduced after the introduction of Individual Electoral Registration. Instead of one person registering everybody in their household, each individual is now responsible for registering themselves. In December 2014, the last registers before the introduction of IER, the average number of voters by constituency was 69,731. In December 2015, it was 68,803. Again, there are substantial differences between constituencies.

Use the dropdown menu below to select the constituency you’re interested in and view key statistics.

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If you would like to access this information in an alternative format please email and we will review your request.


The ONS only provides data on local government electors and attainers for England and Wales. Equivalent data for Scotland and Northern Ireland is not readily available.

In Wales and Scotland, people can vote in local government elections from age 16. Data on local government attainers aged 15 years and local government electors aged 16 years is not currently available from ONS, so local government attainer figures are not shown here for Welsh constituencies. The number of local government voters shown in Welsh constituencies is likely to be 1-2% lower than the true figure.

Data updates

We aim to update this dashboard as soon as possible after a general election, and annually after the publication of the December register. Data shown may not be the latest available. MPs and their staff can contact the Library with queries about election statistics.