The actual time served, however, will amount to about 15 years, the BBC reported.
Gary Dobson, 36, and David Norris, 35, were convicted Tuesday of killing Stephen Lawrence at a bus stop in south east London. Investigators say at least three other white teenagers were involved in the attack.
Dobson will serve a minimum of 15 years and two months and Norris 14 years and three months. Because Dobson was 17 and Norris was 16 when the crime occurred, they were sentenced as juveniles. As adults, they would have faced at least 25 years, the BBC said.
Lawrence's mother says her son's killers should have been tried 18 years ago.
Doreen Lawrence accused police Tuesday of botching the investigation, saying they "failed miserably," The Daily Telegraph reported.
Lawrence, an 18-year-old high school student who hoped to study architecture, bled to death after he was set upon by a gang of white teenagers and stabbed. An inquest found he was the victim of "a completely unprovoked racist attack."
"If the police had done their job properly, I would have spent the last 18 years grieving for my son rather than fighting to get his killers to court," Doreen Lawrence said.
A 1999 investigation into police handling of the case determined the Metropolitan Police were "institutionally racist."