State Prison Overcrowding and Capacity Data
Story by Ryan Spohn, Nebraska Center for Justice Research | Visualization by Mike Maciag
Design capacity: Number of inmates who can be held based on facility's architect or planner.
Operational capacity: Number of inmates who can be held based on staffing and services.
Rated capacity: Refers to inmates or beds a facility can accommodate, set be a rating official.
Prison population: Prisoners in custody of a prison system, "regardless of sentence length or the authority with jurisdiction over the prisoner."
State Specific Notes
- Definitions of capacity used by Alabama, Delaware, Missouri, Nebraska, South Dakota and Texas are different than the federal BJS definition.
- New Mexico and North Dakota figures were imputed by BJS as those states did not submit 2017 NPS data.
- Alaska's capacity figures excludes non-traditional confinement.
- Arizona, Georgia, Idaho, Pennsylvania and South Dakota numbers also reflect private correctional facilities.
- Hawaii's custody count excludes 248 offenders relocated out-of-state.
- Illinois's rated capacity is under revision, according to BJS.
- Indiana's numbers include state-owned facilities staffed with private sector employees.
- Maryland's numbers may exclude pre-trial detainees.
- Mississippi's capacity and custody totals include local facilities.
Prison overcrowding has become a growing social problem in the United States as state incarceration rates increased from the 1970s, peaking in 2008. Although some states have experienced recent decreases in prison overcrowding, often as a result of “justice reinvestment” initiatives and reform efforts, overcrowding remains a significant problem in many state correctional systems. We use data from Table 16 of the Bureau of Justice Statistic’s Prisoners in 2017 report to examine rates of prison overcrowding across states.
Our analysis compares rates of operational capacity across states, indicating that Midwestern states such as Nebraska and Iowa lead the nation in rates of prison overcrowding compared to their rated operational capacity. In comparison to Nebraska’s nation-leading prison overcrowding rate of 127%, New Mexico reported by far the lowest level of overcrowding at 57.4%, followed by Rhode Island at 71.1%. It is worth noting that Nebraska and other select states utilize their own definitions that differ from the federal definition for capacity, so statistics are not entirely comparable across states.
Examinations of prison overcrowding can further be challenging as multiple measures of capacity exist. For example, “design capacity” is the number of inmates a facility can hold according to the architect or planner and represents the lowest capacity estimate, but this measure is not provided by all states. Looking at this latter measure, Alabama leads all states at 167.8% of design capacity, whereas Nebraska comes in second at 154.0%. One additional caveat of state incarceration crowding measures is that they reflect the entire state correctional system, whereas individual facilities within the system may face rates of crowding that are substantially over or under the state mean rate.
Note: Alaska, Connecticut and Ohio did not report 2017 operational capacity data.