Los Angeles sheriff's officials say Lindsay Lohan will likely spend about two weeks of her three-month sentence in jail.
Department spokesman Steve Whitmore says Lohan is likely to be released on Aug. 1 or 2. The projected release date reflects all the credits Lohan is likely to receive.
The department has said the actress was likely to serve a quarter of her sentence or less.
Lohan surrendered at a Beverly Hills courthouse on Tuesday and was immediately whisked away to an all-women's jail in Lynwood. She will serve her time in an isolation unit that has previously hosted Paris Hilton and Michelle Rodriguez.
The 24-year-old's jail sentence began two weeks after a judge sentenced her to three months in jail and another three months in rehab for a probation violation.
McCartney reported from Beverly Hills.