How many people fit in an average prison?

Answer 1

All prisons (worldwide) are overcrowded. An "average" would be impossible to estimate even without over-crowding, since the number would be dependent on the size of the facility, how many 2-person cells they have, how many isolation cells they have, etc.

Answer 2

The average prison in the United States typically holds around 1,000 to 2,000 inmates, but this can vary widely depending on the size and capacity of the facility.