Staff to prisoner ratios in public sector Prison Service establishments are reported as the number of prisoners held in an establishment divided by the number of prison officers (including specialists) employed. The figure does not reflect the number of officers on duty at any particular moment.
The ratio of staff to prisoners varies by category of prison and according to specific local circumstances related to the design and operation of the particular establishment. Differences in the profile of the male and female populations mean that the ratios are not directly comparable.
The ratio of prisoner to prison officers (including specialist) as at 30 September 2015 was 4.8 at male establishments and 3.5 at female establishments.