This briefing paper explores data on the UK prison population, including the population size and change over time, the demographic profile of prisoners, safety in prisons, and the cost per prisoner.

Prisons are a devolved, so UK prison statistics are published separately for England and Wales (the Ministry of Justice), Scotland (the Scottish Government), and Northern Ireland (the Department of Justice). This briefing also compares the UK with other countries.

Weekly prison population data are available for England, Wales and Scotland and quarterly data are available for Northern Ireland. The latest available data show a current prison population of approximately 87,900, comprising

79,453 in England and Wales,

7,004 in Scotland, and

1,484 in Northern Ireland (these at the end of June 2019).

The prison population has fallen since lockdown measures were introduced in response to the Covid-19 pandemic. Since the end of February, the UK prison population has shrunk by around 5,500 people or 6%.

The prison population of England & Wales quadrupled in size between 1900 and 2017, with around half of this increase taking place since 1990. The Scottish prison population almost doubled in size since 1900 and rose 60% since 1990.

The data series for Northern Ireland begins in 2000. Between 2000 and 2018/19 the prison population of Northern Ireland increased by 36%, although the prison population is currently lower than at its peak of around 1,800 in 2014/15.

To put the prison population in context, it is possible to calculate the number of prisoners per 100,000 people in the general population aged 15 and over. At the most recent count there were:

173 prisoners per 100,000 of the population in England and Wales in 2019

in 2019 162 per 100,000 in Scotland (2018/19) and

(2018/19) and 96 per 100,000 in Northern Ireland (2018/19).

International comparisons by Eurostat indicate that, in 2015, England and Wales has the 8th highest rate among EU countries and the highest amongst western European jurisdictions.

The availability of more detailed data on the prison population varies by jurisdiction. Where available, this briefing contains statistics on:

Sentence length and offences for which prisoners were convicted

Age of prisoners

Nationality

Ethnicity and religion

Over-crowding

Safety in prisons (assault, self-harming, deaths in prison, drugs)

Prisoner escapes and absconds

Cost per prisoner

An Excel spreadsheet is also provided which contains the underlying data to the charts in the briefing.