Hilton could spend three weeks or less behind bars because of time off for good behavior and because of overcrowding in the system that has led to freeing some inmates before they complete their full terms, Los Angeles County sheriff's spokesman Steve Whitmore told the Los Angeles Times.

"She will be treated like any other inmate who's classified as a low-level security risk," Whitmore said.

Last year, "Lost" actress Michelle Rodriguez was sentenced to 60 days in jail for violating probation after her drunken driving arrest in Hawai'i. She was released in hours because of overcrowding.

Hilton, 26, was sentenced to jail last week for violating the terms of her probation in an alcohol-related reckless driving case. A judge ordered her to report to the women's jail in Lynwood by June 5.

Hilton intends to appeal and her fans have posted a petition on the Internet urging Gov. Arnold Schwarzenegger to pardon her.